Mega Man X4

Mega Man X4 is the fourth game from the Mega Man X series. It was the second game in the Mega Man X series to be released on the PlayStation and Sega Saturn (although it is the first original game; Mega Man X3 was ported to the system), and was released in 1997. It was later released on the PC in 1998 and then re-released as part of the Mega Man X Collection.

Story
"Many, many years have now passed since Sigma's third defeat and the death of the renowned Reploid scientist Dr. Doppler. After Sigma's plan to use Doppler to spread the Maverick virus failed, Reploids X and Zero have begun to help build a world where no Mavericks exist. Since then, the Reploids are now living in peace with humans, and many large Reploid armies have formed, each one at peace with one another and growing every day. The Maverick Hunters, ever growing, have begun to wipe out the remaining Maverick resistance, and have been heralded as the keepers of the peace. One of the largest and strongest Reploid armies, known as the Repliforce, have developed strong ties with the Maverick Hunters, with their similar ways in honor and the desire for peace. In particular, Zero has befriended one of the leaders of Repliforce, Colonel, so much so that they have become fast friends, and Zero has shown affection for Colonel's sister Iris. Together, the Maverick Hunters and Repliforce protect the world from the Mavericks and ensure peace, but little did they know that their loyalty toward each other was about to be tested. Before long, the Maverick Hunters receive a report that the Sky Lagoon, a floating city in the sky, has been sabotaged to cause it to slam into the city below. All intelligence showed that Repliforce were suspected to be behind the plot. X and Zero respond immediately, heading out to the Sky Lagoon to find answers, little realizing that the true Mavericks are about to pit the Hunters and Repliforce against each other, in a bid to wipe out both sides, unless the Hunters can discover who is really behind the plot before all is lost..."

In-Depth Story
The following is the in-depth story of Mega Man X4, with the events leading up to it and directly following it. Please note that specific dates are unofficial.


 * ca. January 1, 2130 : Repliforce v. 3 is initiated by Cain Labs. General, Colonel, Iris, and all Repliforce personel are created.


 * 2130 : (Mega Man Xtreme 2) When Reploids begin to lose their DNA Souls, Dr. Cain traces the source of this epidemic to Laguz Island. There he finds that a group called the Soul Erasers (Berkana and Gereth) are behind the plot, and after defeating the eight guardians of the island, he confronts them, and ultimately Sigma, foiling the plot.


 * ca. June 1, 2130 : Repliforce v. 3 is deemed "ineffective and potentially dangerous" by Cain Labs. X is made commander of unit #17 and Zero is made commander of unit #0 of the Maverick Hunters.


 * (Mega Man X4) After the Repliforce is deemed to be ineffective, the Sky Lagoon, a floating city, falls onto the city below and kills thousands. X and Zero are sent to investigate and find Colonel on the scene searching for his sister (Iris), and although this seems to be a legitimate claim, the Council finds this suspicious and after that point considers Repliforce to be a group of mavericks. Behind the scenes, a mysterious cloaked figure (Sigma) tries to convince the General to work for him, but at first the General refuses. In the end, the Repliforce rebels against the humans, wanting to form their own society. X and Zero are called by Dr. Cain to put a stop to the uprising and must fight the Reploid leaders of the Repliforce. Then, once the revolt is stopped on the basic level, they have to fight the Colonel, Iris (which greatly saddens Zero, since there seems to be a love interest between them), Double (a new Hunter that was working at the HQ, but who turned out to be a spy), and then the General. However, Sigma was behind the plot and was up in space with them, planning to use a satellite weapon to attack the humans, but Zero and X defeat him and, with the help of the damaged General, blow up the satellite/space station.


 * Early-2130s : Dr. Cain resigns his command of the Maverick Hunters and leaves Cain Labs out of his guilt for the failure of the Doppler Project and the Repliforce as well as the fact that his first creation, Sigma, seemed to be the cause of the ongoing "Reploid Wars" (at the time). He creates a Reploid named Signas, with the most advanced CPU of all existing Reploids, to assume command of the Hunters.


 * ca. 2135 : Dr. Cain presumably dies of old age, probably around 85 years old (based on conjecture).

Gameplay
Mega Man X4 follows its predecessors as the player must combat Mavericks while traversing through obstacles and terrain. Mega Man X4 is the second game to feature Zero as a selectable playable character, but the first game to feature him as a fully playable character (he had limited playability in the previous game). Unlike the future games, you must play the entire game with the character you've chosen only.

The playing styles of both characters differ from each other, giving the gamer a rather varied experience. Mega Man X still copies weapons through defeating bosses, utilizing the long range X-Buster. Zero however, learns techniques called EX-Skills, which mimics an attack used by a boss, often with the use of his close-ranger Z-Saber but none of these except his Giga Crush use Weapon Energy. Because of their gameplay differences, X is often recommended for novice to intermediate players since he can fight enemies from a distance while Zero is used for advanced players as he needs to get up and close to his targets.

The game is also the first to have actual multiple Armors in the game, as well as an 'Armor' for Zero. X can gain the Force Armor like he would any other armor in the previous games, enhancing his abilities further.

Finally, Mega Man X4 is the first X game to use cheat codes which unlock armors specific for the character selected. For X, he gains the Ultimate Armor, which first starts out replacing X's cyan colors with purple. When X visits any of the Light Capsules, he is automatically equipped with the full Ultimate Armor set, giving him a Plasma Shot upgrade and the Nova Strike Giga Attack as well as enhanced defense and the ability to hover in the air (these abilities were also featured on the game's Force Armor, although the latter's use of the Nova Strike is limited). Zero on the other hand gets the Zero Armor, which gives Zero a black sheen and platinum blond hair, but does not affect his abilities in the least. The codes for unlocking these armors differ on the consoles.

Bosses
Eight Mavericks:

Others: 
 * Web Spider
 * Magma Dragoon
 * Storm Owl
 * Split Mushroom
 * Frost Walrus
 * Slash Beast
 * Jet Stingray
 * Cyber Peacock
 * Egregion
 * Colonel
 * Double (If X) / Iris (If Zero)
 * General
 * Sigma

Armors
X's Armors:
 * Standard Armor: X begins the game with this armor.
 * Force Armor: An all-around armor.
 * Ultimate Armor: Obtained by visiting any Armor Capsule after the use of a code.

Zero's Armors:
 * Red Armor: Zero begins the game with this armor.
 * Zero Armor: Replaces the Red Armor through the use of a code.

Trivia

 * It is not known which ending in this game is canon: X's, or Zero's. This stems from the fact that both Zero's battle with Colonel and X's battle with General are referenced by the Skiver in Mega Man X5. It is most likely a combination of the two.
 * Some of the Special Weapons in this game are re-used in the battle between X and Zero (if the player chose Zero) in Mega Man X5.
 * This is the first game to show official names for an armor (Ultimate Armor).
 * It should be noted that this is the debut of the Ultimate Armor and playable Black Zero tricks.
 * Although there are two more games in the X series in that the Final Boss is fought in three battles (Mega Man X and Mega Man X8), X4 is the only game where the player fights Sigma in all three phases.
 * X4 is also the only game in which Sigma uses two forms alternately in one battle, which is the case for the third (final) phase of the Final Boss battle.
 * X expresses fear in the ending that he himself may become maverick. He requests to Zero that, should X ever exhibit symptoms of him becoming a maverick, that he "take care of him".
 * The ending monologue in X's story also seems to implicate foreshadowing that he may become a Maverick in the future as well, hinting his original (or rather, his Copy's) role in the first Mega Man Zero game.
 * Chill Penguin and Blizzard Buffalo make cameo appearances in the background of Frost Walrus' stage.
 * This game marks the first time that a Warning Signal is used when a Boss is about to be fought.
 * On a few occasions, the game may become stuck on a Warning Signal on the Playstation version, forcing the player to have to reset the game. This glitch also occurs in Mega Man X5.
 * Unlike its original series counterpart, Mega Man 8, this game was built for the PlayStation - the Sega Saturn version is a direct port and features no additions over the original version. In fact, many of the special effects were not optimized for the Saturn and are dithered on it. The only enhancements to this otherwise downgraded port is true looping to the music (meaning it doesn't fade out or stop and replay from the beginning), as well as some adjustments to the Frost Walrus stage music and the boss music for the intro stage (adding a crescendo). Finally, there is a new "heat wave" effect in the background of the second half of the intro stage and Magma Dragoon's domain.
 * On the PC version, the music for the final battle with Sigma was switched around. In other words, the music that played for the first phase on the battle on the PSX version became the final phase in the PC version and vice-versa. This can be easily fixed, if one goes into the game's "BGM" folder, and swaps the names of "BGM01.SE" and "BGM02.SE" around. In fact, the game uses regular wave audio files (renamed with a ".SE" extension just to fool you), so, any music that the player wants to hear can be placed anywhere throughout the game, as long as it's in .wav format, by simply renaming any desired wav files with the appropriate BGMXX.SE title and placing it in the BGM folder, making sure to back up the original files. Mega Man X5 on the PC works in the same manner.