Glitches

This is a list of glitches and bugs in the Mega Man series, which are caused by programming errors. They may be harmless or hazardous. Some glitches are often exploited in Speed Runs, especially when tool-assisted.

Mega Man
If the game is paused with the Select button, it is possible for Mega Man to avoid damage and make his attacks hit multiple times. This is most effective with the Thunder Beam, especially when fighting the Yellow Devil. This is because enemies' "invincibility timer" doesn't freeze when the game is paused, so waiting till it ends and then unpause causes the enemy to get hit again. It is important to note that this glitch was removed from later versions and ports of Mega Man, as the pause button gets disabled briefly during the timer in effect. It only works on the original NES game, Mega Man Anniversary Collection and Mega Man Legacy Collection.

In Ice Man's Stage, in the tallest area just before the first screen transition, if the player rapidly presses left and right on the D-pad while jumping to prevent slipping, varying errors may occur, in a glitch known as Arbitrary Code Execution. Depending on what frame you successfully perform this, the game will load different assets. This is caused by an object that unloads the Pepe spawn object being constantly loaded and unloaded.

Using the Magnet Beam in a specific way or another glitch causes Mega Man to zip through stages. Other glitches include being hit before entering the boss room.

In Fire Man's stage, falling from a Magnet Beam in the room with the fake hole in the center will lead to Mega Man falling through the bottom of the "hole" and getting stuck in a wall in the room below. If Mega Man is facing left he will zip through the wall.

When two ladders exist in the same horizontal position at the top and bottom of the screen and Mega Man can jump higher than the screen boundary, Mega Man can use the top ladder to wrap through to the bottom ladder as a shortcut. This can be easily done in Cut Man's stage (the room with the first Flying Shell) as well as Dr. Wily stage 1 (the zigzag room with the spikes and the Killer Bomb).

When a Flying Shell is hit with Ice Slasher and, while frozen, is either destroyed or goes off-screen, it will stop appearing. This can also be done with Pepes and Killer Bombs, although they will sometimes still respawn. Jumping above the screen boundary will also stop constantly-spawning enemies.

Jumping above the screen boundary in Fire Man's stage using a Magnet Beam leads to death, as the game thinks you wrapped around the bottom of the screen into a bottomless pit.

At the final boss, if you get hit at the same time Wily Machine's first phase is defeated, pressing START repeatedly may cause Mega Man to constantly dart to the top-left part of the screen. You may end up in a glitchy corridor before the boss (as seen in the picture below). This can be done over and over again until Mega Man runs out of health.

Sometimes, at the end of Bomb Man's stage, the Sniper Joe in the upper room may get stuck on the wall when following Mega Man.

If you land on the ground after the final hit on the second phase of the Wily Machine (easily done with Rolling Cutter) and walk to the left, you will be in the "anti-chamber" (as seen below) unable to move.

In Elec Man's stage, the room where you can get the Magnet Beam has a ladder that doesn't go all the way down to the floor. If you move in front of the ladder and hold down on the D-pad, Mega Man will constantly move left and right, changing the direction he's facing at a fast rate of speed.

Some Robot Masters may end up stuck in the teleporter in the Boss Rush. If this happens with Guts Man, the screen will continuously shake since Guts Man keeps hitting the teleporter ceiling and attempting to jump again, causing earthquakes. This can make it impossible to continue fighting as Mega Man keeps falling over. Bomb Man can also end up stuck in the teleporter.

Mega Man Powered Up
When using Guts Man, using the Super Arm on some bosses may leave them stuck in a pattern. This is most notably when facing Elec Man, as using Super Arm in the beginning of the battle will make him walk on the summoned block until it is removed, allowing for an easy victory.

When using Time Man, his projectiles may pass through walls when fired in a specific point between a wall and a spike. This is notably useful to complete his ninth challenge in a short time.

A well known glitch in custom stages involve making custom boss rooms, involving placing the tiles along with a ladder in Construction mode in front of the boss door, with the boss room the creator want under the original boss room, jumping near the tiles and glitching through it into the original boss room, most of the time, the player and the boss will sink into the custom boss room. One can even have recovery items and enemies in the custom boss room.

Mega Man 2
When fighting a boss in his stage, touching the shutter may transport Mega Man to a glitched version of the Wily Stages. This glitch does not work in the European version, most likely due to the lower frame rate causing less lag.
 * Wily Stage 1 - Heat Man's stage, Bubble Lead
 * Wily Stage 2 - Air Man's stage, Item-1
 * Wily Stage 3 - Wood Man's stage,  Item-1
 * Wily Stage 4 - Bubble Man's stage, Item-1
 * Introduction screen - Crash Man's stage, Item-1Mega_Man_Legacy_Collection_20190908091620.jpg

Like the first game, a glitch can cause Mega Man to zip through stages.

By changing certain Special Weapons, it is possible to use them indefinitely, as their energy will not decrease. This is due to 1 unit in the gauge being less than 1 in the total. For example, Metal Blade, with full energy and without recharging, can be used a total of 112 times, 4 times per unit. Using it 3 times, changing to another weapon, and equipping it again will reset the unit to 4. This can also be done with Quick Boomerang and Bubble Lead.

In the beginning of Wily Stage 1, Item-3 can be used in the left corner despite the lack of a wall. It can also be used in a small area in the beginning of Wood Man's stage.

If Pierobot goes off-screen before landing and his gear doesn't disappear, it will move in the air.

In Wily Stage 1, there is a ladder that also does not go all the way down to the floor. If you use Item 3 in the narrow space and reach the top of the ladder, you will not transition upward to the next screen. You will instead get stuck up in the small area (until Item 3 runs out of energy) whilst hearing a strange buzzing noise.

The same Elec Man ladder glitch can be done while using Item-3, holding down on the D-Pad, and being in front of the bottom of a ladder.

If Time Stopper is used in a room with a Friender before it teleports in, Mega Man won't be able to pass the area it will appear as the game reads that it is already present. However, using Time Stopper before entering the room will allow Mega Man to pass as the Friender won't start teleporting.

Using the Leaf Shield to finish off a boss can cause it to stay out, and its sound drowns out part of the music. After reaching Stage Select, it will stop.

In the Mega Man Mobile port of the game, if Time Stopper is used near the end of Air Man's stage, there is a possibility that the weapon energy for it stays stuck and that the time stop stays on screen for the entire level, this will cause Air Man to glitch so the fight can't begin correctly.

Pausing the game when Wood Man jumps will make him move up further. By pausing continuously one can leave him away from the ground and defenseless.

In Wood Man's stage, if you follow a Atomic Chicken (in the area they spawn in) all the way to the left wall, they'll walk straight through the wall.

If you kill a Pierobot bouncing on its giant gear before it falls down (without destroying the gear), the gear will slowly fly around in air until it goes offscreen.

Sometimes, if you do these two things at the same time when an enemy hits you: (Shoot a non-charged Atomic Fire and tap LEFT or RIGHT), Mega Man's leg will glitch and appear to be made of Life Energy. This will only appear quickly.

Picking up a large Life Energy or Weapon Energy while taking damage will cause Mega Man to take damage again (or die, if he landed on spikes or lava when he picked up the item) after the energy has been filled, due to the energy refill's pause effect ignoring invincibility frames.

Pausing and resuming while in mid air causes Mega Man's vertical speed to reset.

Holding the fire button while entering the shutter to Crash Man's room causes Crash Man to not retaliate as long as the fire button is held down. This can be done with Quick Boomerang due to that weapon's ability to auto-fire. He may however occasionally jump and fire a single Crash Bomb as this is part of his AI when Mega Man is not fighting back, but this is rare. This glitch was fixed in Mega Man: The Wily Wars as well as with the Doc Robot mimicking Crash Man in Mega Man 3 (when using Needle Cannon in place of Quick Boomerang).

Entering a boss room with a charged Atomic Fire causes the weapon to be fired even if the button wasn't released, wasting the shot.

Quick Man's seemingly-random AI is literally caused by him being too quick, which usually gets him stuck a few pixels inside walls. His AI consists of just three moves: jumping once without attacking, jumping a second time and throwing boomerangs, and then running at the player for a set distance before the pattern repeats. However, if he ends up in a wall due to his speed, the jumping moves end after one frame due to him hitting the "ceiling" of the wall, which causes the next part of his pattern to start, which usually ends up causing him to throw boomerangs after the first visible jump, or simply running at the player without jumping at all. His only programmed randomness is the height of his jumps. In Mega Man: The Wily Wars however, his moves really were randomized, making him much harder to defeat.

If Mega Man dies at the same time as a boss is destroyed, his explosion graphics will remain on the screen after he teleports out, and it will still count as beating the boss. Other games, including the first, consider this to be a failed battle, causing you to have to fight the boss again.

If Mega Man is hit while the game is lagging, he falls back twice the normal distance. Due to the lag that occurs when fighting the Mecha Dragon, getting hit by its fire usually means death by bottomless pit if the player isn't standing on the top platform.

Mega Man 3
Using the second controller may cause various effects, such as a super jump, invincibility (if Mega man collects energy item, he is no longer invincible though), and freeze the game. This glitch was removed from the European version of the game and can only be done on the Japanese and US versions.

In Shadow Man's Doc Robot stage, on the second screen, sliding or jumping into the spikes, frames before the screen switches, the death noise plays, but the music stops. You can still complete the stage as normal. This can also be done on Spark Man's Doc Robot stage after defeating the Doc Robot imitating Metal Man.

In the pause menu, after obtaining the Shadow Blade or Spark Shock, highlighting the weapon and pressing the right button will respectively select the Rush Jet or Rush Marine, even if they were not obtained. By doing this, it is possible to use them earlier, but first they need to be recharged with Weapon Energy. To keep Rush Jet and/or Rush Marine permanently, Rush Jet/Marine must be used for at least 1 bar of energy, otherwise they will disappear from the menu. After clearing the stage, they will become available even if Needle Man and/or Shadow Man haven't been defeated yet. This cannot be done on the later ports or remakes of the game, with the exception of Mega Man Legacy Collection.

When entering a room that Proto Man appears, pause the game before landing on the floor to hear his whistle beyond the part it is interrupted.

In Gemini Man's stage, there is a large dome which Proto Man will destroy in order to let you continue. If Mega Man slides immediately before entering this screen and jumps as far as he can, he will fall through the dome and the Proto Man whistle will continue to play, eventually ending and the music remaining silent for the rest of the stage until Mega Man dies or enters the fight with Gemini Man. Some parts of the stage will have glitched graphics if this is done, notably the Penpen Makers.

The screen transition just before the second Tama in Top Man's stage can allow you to slide on air just before and while transitioning.

Normally, if you slide through the shutters before a boss room, Mega Man will automatically start walking when the screen scrolls. If you slide into the shutter before Gamma, Mega Man will actually keep sliding. Mega Man would only be able to slide through shutters starting with Mega Man 5.

Occasionally, you can fire a weapon while entering a boss room. For example, firing a Magnet Missile while entering Shadow Man's room will cause the magnet to hit Shadow Man and bounce off, as Shadow Man is immune to this weapon (Though this doesn't seem to be the reason, as hitting Snake Man with a Mega Buster shot will do the same). Other weapons such as Hard Knuckle may go right through a boss without hitting it.

Sometimes when fighting Gemini Man or Doc Robot (Heat Man), your shots will not appear if the boss fires at the same time even though Mega Man is in his firing pose.

If Doc Robot (Flash Man) uses the Time Stopper and you are firing, your invincibility frames are ignored and Doc Robot's shots will hit multiple times.

When using Top Spin against Shadow Man, the weapon energy may completely drain itself in a single hit. This also happens against Doc Robot (Crash Man), and against Top Man during the rematch. It does not seem to happen against Doc Robot (Heat Man). It also happens if an enemy is immune to Top Spin, for example Hammer Joe or the Cannons on Needle Man's stage. This glitch was fixed in Mega Man: The Wily Wars.

With a Rush item selected as the current weapon, you can normally fire two shots with the buster. Unlike normal shots, you can actually pause the game with these shots on-screen, and when resuming, the shots do not disappear unlike Mega Man 4 and later. If you switch weapons with the shots still on-screen, the shots gain the same attributes as the current weapon. For instance, selecting Top Spin will turn the buster shots into Top Spin buster shots, which carry the same weakness data as Top Spin itself e.g. destroying Gamma in one or two hits, or 7 damage against Shadow Man instead of 1, or merely bouncing off Hammer Joe who is immune to Top Spin. Note that Gamma is immune to the regular buster and the shots would normally bounce off, but the game actually thinks that you are firing Top Spin shots at him, not buster shots. This can be done with any Rush item, be it Rush Coil, Rush Marine or Rush Jet.

On the European version of the game, during the battle against Wily Machine 3 the floor constantly shakes up and down and glitched zeroes will appear in the floor. This is because Capcom did not alter the 60 Hz timing of the game program for the 50 Hz PAL console. If the same cartridge is used in an NTSC console (assuming the console has no regional lockout e.g. NES-101 Top-Loader), the glitch does not happen as the frame rate is correct for the game, however the sound effects and music will be higher pitched than normal.

Mega Man 4
Using Wire adapter in a scrolling stage causes Mega Man to slide and he launches up into the sky when he goes off of the platform. When near near the end of the scrolling section in Dr. Cossack's Citadel, Mega Man will be stuck in "space" unless he deactivates Wire.

If the Wire adapter is used to beat the boss of the third level of Dr. Cossack's Citadel player is still with wire adaptor still on, mega Man will fall on spikes without dying.

If player uses Flash Stopper when the Cockroach Twins are defeated, it will freeze time infinitely, leaving the player no choice but to jump onto the spikes and start over from the checkpoint.

If Tako Trash is hit with Drill Bomb, Mega Man will be able to move through its body without taking damage. Also, even though Tako Trash is immune to Skull Barrier, after hitting him within Drill Bomb, he will then take 1 unit of damage from Skull Barrier.

After defeating the Wily Machine 4, Dr. Wily flies away in a machine. While he is going up, if he is hit him with Rain Flush, he and his capsule will explode, "killing" him. Doing this will leave the player stuck in the room and unable to beat the game, requiring the player to reset the game.

Using Flash Stopper right before the victory sound will make all of the black colors in the background stay white. This also works before Mega Man lands to ground when encountering boss.

When selecting a weapon before Pharaoh Man's fight begins, it will cause his sprite to go weird. This works in the Mega Man Legacy Collection.

In the part where the pistons are in Dust Man's stage, shoot at the blocks for the Metall EX. Make sure it's high. Let it go in the spot of blocks. If done right, Metall EX floats in the air.

If player enters Skull Man's boss fight and uses Balloon, Skull Man won't move, although the player can move and shoot. Unfortunately, he cannot be harmed as well causing the player being unable to beat the game.

If the player uses Rush Marine in a short space, Mega Man will die when he enters Rush as it considers that he was crushed. Also, if Rush Marine is called in front of a high area, Rush may pass the floor and appear in the space available below.

In the water section of Dive Man's stage, if you go up to the top of the screen using Rush Marine, he will "fly" through the air, or at least hover above the water. The water can sometimes drag you back down.

Mega Man 5
In Wave Man's stage, using Super Arrow to jump over the Marine Bike will make Mega Man move on the water. He may get stuck in the area, but it is still possible to get the other side of the stage if the player stays on the screen.

In Gravity Man's stage, holding up and right when attempting to get to and climb the upside down ladder will result in Mega Man constantly seeming to jump and glitch around in the air. This glitch is not harmful.

Also, in Gravity Man's stage, spamming left and right in a gravity changer when a enemy which is affected by gravity, there is a chance that the enemies' gravity will flip.

In Wave Man's stage, it is possible to jump over the motor boat and transition to the next screen. Mega Man will stand on the water and slide to the far end of the screen. The farthest you can go to is until the mini-boss. You will not be able to control Mega Man after this. The Octoper OA will fire backwards even though he is facing forwards

In the last Dark Man stage, it is possible to not break all of the cracked blocks and reach the top of the screen (Tip: Use Super arrows as extra platforms). Despite this, you are still unable to go through the shutter.

In the "cutscene" with Proto Man revealing Dark Man to Mega Man, if you charge your buster when you enter the room, sometimes Mega Man will stay the color he is in the whole cutscene. When Proto Man gives Mega Man the L-tank, the L-tank will also be the same color as Mega Man, which is what's supposed to happen if Mega Man is regularly charging.

If you are quick, you can select your weapon while in a boss room, but not when the boss music starts playing. This is easiest to do with Gravity Man. This is also possible to do in Mega Man 3 and Mega Man 4.

Mega Man 6
Although difficult, it is possible to slide in the air to pass the Count Bombs before the boss room in Blizzard Man's stage. There is a weapon exploit in this game. To start, enter a password giving you only the Energy Balancer, which you can make here. Then, go to Flame Man's or Plant Man's stage. Then, open your weapons menu and highlight the M. Buster meter. Then, you must press right on your directional pad, and exit the menu. Now, you must venture through the stage, collecting Weapon Energy capsules along the way. You may notice that your Energy Balancer is still picking up the capsules, though you don't have any weapons. After a while, you will notice that the Balancer is no longer picking up energy. This means that a meter is full. Going into your menu, you will, oddly, see a Beat plate. After seeing this very odd thing, exit your menu, reach the Robot Master, and beat it. But when you go to the stage select, the enemy would have been defeated. Heading into your next stage, you should have two weapons you didn't get.

Mega Man 7
Using Noise Crush just before entering the boss room may cause it to hit the boss, instantly killing him if timed right. This works primarily with Spring Man and Turbo Man. Doing so with Cloud Man (done with Danger Wrap instead) causes the room to glitch out and eventually kills Mega Man.

Mega Man 8
If Tengu Man is defeated while Mega Man is stuck in his air sphere, the player will be able to move after his explosion. If the player falls in one of the pits after taking the Evil Energy, Mega Man will return to the checkpoint and Tengu Man must be defeated again.

Mega Man & Bass
By using Lightning Bolt, the player can avoid the Monking A scene in King Stage 1. Also, Ice Wall can interfere with the scene.

Mega Man: Dr. Wily's Revenge
If you press a button on the D-Pad at the same time when you select a Robot Master, if timed correctly, the Robot Master will jump towards the center as parts of the background move up and down endlessly. The Robot Master's name will not appear, and the stage will never start, forcing you to reset.

Mega Man II
Metal Man may get stuck on walls.

In Metal Man's stage, Mega Man may receive damage for no apparent reason in one area. This is due to Moles appearing beyond the point they are supposed to.

If you use Hard Knuckle right before transitioning the screen down, it may cause strange effects if timed correctly. You can use this to corrupt the entire game in a certain case, but if used incorrectly it can crash your game.

When you first reach the checkpoint in Crash Man's stage (with the mountains in the background), there is a ladder to the left that you climbed to get there. If you go off-screen and come back, there will suddenly be Tellies spawning next to the ladder.

Mega Man IV
If the rain from Rain Flush solidifies the quicksand on Pharaoh Man's stage when a Sasoreenu in burrowing, the Sasoreenu will be paralyzed and becomes invincible.

Mega Man V
There is a glitch that allows the Black Hole to damage and defeat the first form of the Brain Crusher by using it at point blank range. If the first form is defeated this way, the game will cut straight to the cutscene preceding Sunstar, skipping the Brain Crusher's second form.

Mega Man (Game Gear)
If you pause and unpause when you touch the boss door, the door may still appear partially opened as you walk through it.

Mega Man (PC)
You can get a Nuclear Detonator to get stuck in a wall if you simply stand right in front of a wall and fire it, as shown in the picture to the right. You can also get a Sonic Wave stuck in a wall. It will bounce a few times inside the wall very quickly before disappearing.

Mega Man X
Although the player is not supposed to die against Vile with a Ride Armor, as he will try to capture X when his health is low, dodging his capture beam and getting contact damage will eventually result in X's death. Also, if X and the last Road Attacker kill each other, Vile will still appear and grab an invisible X.

In Flame Mammoth's stage, it is possible to get above the ceiling by using the scrap Utuboros heads to jump into the tubes they fall from. This doesn't work in the European version.

In Storm Eagle's stage, using Boomerang Cutter on the Life Up and dashing to the right to catch it while falling may cause a platform to appear on the Boomerang Cutter. The timing is difficult, but when well used, this platform can be used like a magic carpet, flying the player to the end of the stage. Doing this will also cause several errors, like a glitched background and invisible enemies.

Shotgun Ice can be used to glitch in walls and skip the rematch against Armored Armadillo in Sigma's fortress. If you jump to make Armored Armadillo appear, he'll look glitched, but you can continue the stage like normal while the boss theme is playing, without killing him still.

It is possible to skip the dialogue between Vile and Zero in Sigma's fortress by using Wall Kick to avoid touching the floor and use the walls to reach the door to Vile.

If the player manages to make Vile turn around after he captures X (being possible with a charged Homing Torpedo), he will walk backwards endlessly, preventing the player to continue.

If passwords are used to finish the game without the Foot Parts (which can't be avoided normally), X will have the Foot Parts in the scene showing Sigma's fortress collapsing, and his legs will vanish when he does a dash in the ending.

Mega Man Maverick Hunter X
In Armored Armadillo's stage, if the player reaches the boss door while stepping on the right tip from the last mobile platform, it can make X get stuck in a walking animation without moving to the next room, making it impossible to continue unless the player exits the stage or restart the game.

Mega Man X2
Using Shoryuken before the sub-boss in Magna Centipede's stage will activate the Zero/Black Zero scene and following events, allowing the player to skip the boss rematches.

In the final stage, when X reaches the room where Chop Register was fought and uses the Shoryuken at a certain distance, he may end up in the centre of the room during the following cutscene. If the player obtained all three of Zero's pieces, X will immediately fall through when Zero punches the hole in the floor, although Zero will continue with his dialogue. If the player does not close the dialogue box, Sigma's pre-fight dialogue will eventually override Zero's and when it closes, the player regains control of X earlier than they're supposed to. If the player preforms a Shoryuken while Sigma's life meter is filling up, X will become invincible during the fight until he preforms another Shoryuken or reaches Sigma's viral form in the second half of the fight.

In X2 there is a glitch nicknamed the "Neon Jump" which allows to reach areas that are in normal ways inaccessible at the time. The player needs to first get the Arm Parts and the Foot Parts upgrades, then fully charge the buster and fire one shot. X will be left with one remaining charged shot to fire without holding the button down, next, one has to press Jump, Air Dash, and then press the Fire and Jump buttons at the same time. This allows X to Jump again in the air and being able to do another Air Dash.

Mega Man X3
If Zero Change is done while sliding down a door (if the door isn't aligned to the wall, an air dash can be used to reach the top of the door), Zero will enter the next room, allowing him to fight against most sub-bosses and the Nightmare Police. This glitch can't be used on bosses due to lack of space for X to jump and air dash to the top of their doors. Of note, while there is enough room to do this before Vile MK-II in the second Doppler Stage, Zero Change is not available due to the area before him being Volt Kurageil's boss room.

Blizzard Buffalo has a glitch that causes him to ram away from X.

In X3, the "Neon Jump" is even more reliable as one can reach places even more higher up that can't be reached in normal gameplay by any means. The Neon Jump in X3 has more varieties. The normal Neon Jump, which can be done like in X2, and the enhanced Neon Jump, which allows for more upwards movement due to being able to dash upwards. One can also do a double Neon Jump, which involves Jumping, doing an Upwards Dash, Fire and Jump at the same time, repeat one more time. And the "Ultimate Neon Jump" which requires the Buster Chip or the Gold Chip upgrade. One has to select Hyper C. and do the same proceedure of the Double Neon Jump, however, this time, one can do plenty of Neon Jumps until the Hyper C. energy runs out, allowing for almost unlimited aerial movement.

Mega Man X4
Web Spider can be glitched if a Charged Twin Slasher is fired specifically when Web Spider's sprite is just touching the top most of the screen when climbing up. This will result in Web Spider glitching on top of the roof and then going back down, attempting to restart the fight but getting frozen. Further attempts at breaking the electric web will just result in Spider glitching out more. This will soft-lock the game, only able to restart it by killing X with the electric wire.

Zero is able to cancel his Z-Saber slash by Dashing, this technique is nicknamed "SDC". This can be done in succession to drain the health of most bosses as the first slash won't make bosses be in hurt state for long. This can be done in X4, X5 and X6.

Mega Man X5
A glitched Lifesaver will show up if the player equips the Shot Eraser part and uses it in the fight vs Ultimate Armor X to destroy a Plasma Shot at about the same time it hits a wall. This Lifesaver sprite has a hitbox.

Players can use Wing Spiral to reach Items that are supposed to be obtained with armors as the weapon slightly raises X up in the air. This can be done by firing a Wing Spiral, then inmmediately pause and switch to another weapon, then pause again, switch back to Wing Spiral and repeat. This can also be used to skip Dark Necrobat's autoscroll section.

Mega Man X6
One can make Zero invincible to enemies and hazards by performing an Ensuizan before falling off of a slippery surface or on top of a destructable platform. As Zero's Ensuizan gives him invincibility for a few frames, the flag to make Zero hittable again is cancelled by his falling animation. In order to no longer being Invincible again one has to perform the Ensuizan again. Entering in in-game cutscenes also cancels the invincibility.

Guard Shell has a glitch when used by Zero, as it allows to do damage to enemies with every frame of the saber animation. This is considered to be superior to the "SDC".

Mega Man X8
Zero and Layer can fly up when using Rasetsusen.

Mega Man Xtreme 2
Using Giga Crush while on a ladder will result in a glitch.

In Wire Sponge's stage, when the player makes it to the first set of floating platforms and jump up to where is an 1-UP, switching to either X or Zero will cause the 1-UP to turn blue or red. Zero's 1-UP turns blue while X's 1-UP turns red. It's a harmless glitch and it will still function as a 1-UP.

Mega Man Zero
Triple Rod.

Mega Man Legends
By using the Jet Skates, Mega Man Volnutt can pass a wall in the Underground Ruins.

Zenny from Data in the Flutter.

The PC version contains several bugs.

Mega Man Legends 2
Unequipping the Blade Arm during the jumping slash will make Mega Man walk in the air until he jumps or is attacked.

The PC version contains several bugs.

The Misadventures of Tron Bonne
In Gold City, forcing a NPC to move to the mountain will leave him stuck in the air.

Mega Man Battle Network
If MegaMan.EXE is far from the enemy in a battle, normally the Mega Buster fires slowly, while it fires faster the closer he is to the target. However, the player can increase the speed by "step buffering" which is constantly moving and shooting to cancel out the rest of the buster animation.

When using the Chip Trader, one can save before inserting Battle Chips and soft reset the game if you do not get a chip you want. Capcom fixed this in the later games by requiring you to save when you insert chips.

Mega Man Battle Network 3
If the player uses NaviCust programs to increase the folder's regular memory to equip a Battle Chip with high memory as the regular chip and removes the NaviCust programs, the chip will be removed from the standard folder if its value is higher than the limit without the programs, but this will not occur in the second folder.

There is a way to turn the regular chip into a different chip from the folder in battles.

Mega Man Battle Network 4: Blue Moon
When WoodMan's scenario is triggered (the event with the wooden stakes popping up through the ground), when a virus battle is concluded in any way, the game will experience massive slowdown until Megaman jacks out. Since it triggers by entering and concluding a battle, that means you can use sneakrun to avoid the glitch. This mainly occurs when playing on the Nintendo DS, but some people have claimed to experience the glitch when playing on a Gameboy Advance or on an emulator. This glitch was fixed in the Wii U Virtual Console re-release.

Videos
Mega Man 1 - https://www.youtube.com/watch?v=BfV3qza-W8Y

Mega Man 2 - https://www.youtube.com/watch?v=zjsMkMqrbqE

Mega Man 3 - https://www.youtube.com/watch?v=RH7Gq_MDyWg

Mega Man 4 - https://www.youtube.com/watch?v=yppHLrWj-ZI

Mega Man 5 (PT. 1) - https://www.youtube.com/watch?v=EY7Ps90G06w

Mega Man 5 (PT. 2) - https://www.youtube.com/watch?v=GCDL-6jflGg

Mega Man 6 - https://www.youtube.com/watch?v=ueBRv0kAi40

Mega Man 7 - https://www.youtube.com/watch?v=b_Z18r2DoMo

Game Genie Glitches Videos
Mega Man 2 - https://www.youtube.com/watch?v=Rd2uCL_8qaY

Mega Man 6 - https://www.youtube.com/watch?v=QUPz0k8iA0M

Video Credit
GeminiLaser