Challenge

Challenge is an extra game mode from Mega Man Powered Up, Mega Man 9, Mega Man 10, Mega Man Legacy Collection, and Mega Man Legacy Collection 2 with optional challenges that the player can try to achieve. Those vary by being small stages with their own challenge or an objective to be done in the main game mode.

Mega Man Powered Up
Mega Man: Powered Up has 100 challenges, being 10 for Mega Man (available from the beginning), 10 for each of the eight Robot Masters (the character must be unlocked to play his challenges), and 10 being boss battles (unlocked after completing the game. Except for Old Style, all character can be used). Although optional, completing all challenges will make Proto Man available as a playable character.

Mega Man 9
If certain challenges in the main game are accomplished, then players gain the following recognition for it.

Mega Man 10
Mega Man 10 has two types of challenges. The game also gives a rank for the challenge completion, starting with Rank E at 0%. Completing 25% of the challenges will increase the player's rank to D, Rank C with 50%, and so on until Rank S with 100% completion.

Challenge 1
A series of small stages with specific conditions to be completed. Challenges 38 to 88 are unlocked by meeting the specific sub-boss or boss (all varieties with The Keeper and Weapons Archive) in the specific difficult (Easy/Normal/Hard) in the main game. Challenge 1 is 98% of the total, challenges 1-25 being equal to 1.4 % from the total each, and each goal from challenges 26-88 are 0.5 % from the total.

Challenge 2
Challenges for the main game. Except for Superhero (Hard only) and Headbanging (Mega Man only), all challenges can be done with any character in any difficulty. Challenge 2 is made of 2% from the total. Additionally for the Xbox 360 and Playstation 3 versions, completing a Challenge 2 requirement can also count to earn the player an Achievement/PSN Trophy for that particular challenge.

Mega Man Legacy Collection
In Mega Man Legacy Collection, Challenge Mode allows the player to play different aspects from Mega Man through Mega Man 6 in fifty-four separate challenges. One aspect is traveling through parts of different stages where the player must reach the black hole that functions as a portal which will transport the player to a different stage area, while another part is facing bosses, both Robot Masters and the fortress bosses, most notably the Wily Machines. The bosses from Mega Man 2 will take the same amount of damage from MM2's Difficult Mode. The player must complete the challenge within the time limit that is listed and can earn bronze, silver, or gold medals depending on how fast they completed the challenge. Only the Switch version allows the player to see how faster they would have to go to earn a gold medal if they fail to do so on their first try.

Unless if restricted, Mega Man can use any of the Special Weapons and other special equipment from that respective game, with their weapon energy automatically re-filled when transporting between different challenge areas. However, the current energy in the life meter will not regenerate and any collected Energy Tanks will disappear unless if used before the player enters the portal. Mega Man can also have unlimited lives, however the time cannot be reset when he dies and he must always start over at the beginning of the current area within that challenge, therefore this gives the player less time to be able to complete the challenge within the time limit.

It should be noted the game's special pausing (from opening their special menu) is the only way to pause the clock as opening the regular menu (or using MM1's pause glitch) will still run the clock.

Additionally, with the exception of the Nintendo 3DS version, the game also has a scoreboard which allows for the players to view other players' scores and also to watch their replays from the highest ranking score. Also the Nintendo Switch version allows for the rewind feature to be used during any of the video replay.

Unlock Requirements
At the beginning only a few challenges will be available, but by completing the challenges more will become available.

Nintendo Switch/3DS challenges
The versions for the Nintendo Switch and 3DS can also have eleven additional challenges (ten of them submitted by fans in a contest) that are obtained with both having the New Nintendo 3DS/2DS or Nintendo Switch, and the Mega Man amiibo from Super Smash Bros. for Nintendo 3DS / Wii U. The bonus challenges were submitted by:
 * Amie Falamie
 * Brandon Valenzio
 * Jason Marciniak
 * Jerry Allshouse
 * Joseph Collins (Wily's Machines)
 * Joshua East
 * Keelan Clifton (No Swimming Allowed)
 * Nathaniel Hoover (Fortress Fun House)
 * Nikias Källarsson
 * Tom Lyman

Mega Man Legacy Collection 2
In Mega Man Legacy Collection 2, much like the original Legacy Collection, players can play through different aspects from Mega Man 7 through Mega Man 10 which are listed under "Extra Challenges". Unlike the original, the challenges are now separated between each game, so now players can no longer go between different games during each challenge. However, the challenges between each game are mostly the same now and not as diverse, which only focuses on two Stage Remixes, as well as fighting the sub-bosses, Robot Masters, Fortress Bosses, Fake Man from Mega Man 9 and the Mega Man Killers from Mega Man 10. Another improvement is aside from the time to collect the bronze medal, the times required to collect the silver and gold medals are now seen on the screen as well. Most challenges for Mega Man 10 are treated on the game's Normal Mode difficulty level, with the minor exception of Stage Remix 4 in the amiibo challenges which is instead on Hard Mode.

For Mega Man 9 and Mega Man 10, extra challenges are available which are different variations of regular challenges where the player can use Proto Man or Bass instead (with the exception of the Buster Only challenges). Also, the challenges from the original release of Mega Man 9 and Mega Man 10 are listed under "Original Challenges". There are also a few gameplay elements that are removed during the challenges, one example being the Special Weapons of the Mega Man Killers from Mega Man 10.

Much like with the original Legacy Collection, watching video replays of your own score and the scoreboards are available to view other players' scores. The ability to watch other players' replays are also available in most versions with the exception of the Nintendo Switch version.

Nintendo Switch Challenges
Much like with Mega Man Legacy Collection, the Nintendo Switch version of Mega Man Legacy Collection 2 has 10 new challenges unlocked by using the Mega Man amiibo from Super Smash Bros. for Nintendo 3DS / Wii U which is accessed from the option menu on the main screen.

Each of these challenges are extra Stage Remix challenges of going through different points in different stages from each game. While the games each have a Stage Remix 3, only Mega Man 10 has a Stage Remix 4. Much like with most of the earlier challenges, the new Stage Remixes from Mega Man 9 and Mega Man 10 have extra variants, with a separate version available for the player to use Proto Man or Bass.

Completing any of these challenges can also count as part of the unlock requirements of being able to unlock other challenges as well for that particular game.

Trivia

 * A glitch causes Time Man's attack to pass through walls when fired in a specific point between a wall and a spike, allowing players to complete his ninth challenge in less than four second.