The PlayStation version was later re-released as part of the Mega Man Anniversary Collection, and was released on the PlayStation Network as part of the PS1 classics on December 17, 2014 in Japan and May 27, 2015 in the U.S.. The PlayStation version was also later re-released as part of Mega Man Legacy Collection 2 on August 8, 2017 for the PC, Playstation 4, and Xbox One. The Nintendo Switch version of Legacy Collection 2 was later released on May 22, 2018.
In the year 20XX, two strange beings are fighting each other in outer space. As they collide into each other, they start falling towards Earth. Meanwhile, Bass and Mega Man are fighting on Earth, but the battle is cut short when Roll calls Mega Man. Dr. Light tells them that a strange meteor with a powerful energy signature has fallen on an island, and Mega Man is sent there to retrieve the meteor before it falls into the wrong hands. However, the island was Dr. Wily's current secret base, and he escaped with the extraterrestrial energy from one of the robots. Mega Man found the other robot badly injured in a crater and sends him to Dr. Light to be repaired.
Mega Man defeats four Robot Masters that attack various places on the globe and, when he returns to Light's Lab, he brings a mysterious energy found in the robots and finds that the robot is undergoing repairs. Then, while talking to Light, the robot breaks free and heads out into the desert. Mega Man follows him and they fight briefly. Proto Man intervenes in the battle and tells Mega Man that Wily's new fortress, "Wily Tower", is up ahead. Mega Man goes ahead and is captured by one of Wily's robots, but the robot he fought before saves him and introduces himself as Duo. Duo explains that the other robot contained "Evil Energy" within it and that Wily was using that energy to make his robots more powerful. Mega Man needed to destroy the energy sources from the barrier protecting the Wily Tower, which was being protected by four Robot Masters.
After destroying the second four Robot Masters, he enters Wily Tower and fights against Bass and Treble, and, in the end, Dr. Wily. Mega Man was injured by the Evil Energy in the process, but Duo saved him and left him out in the desert, where Proto Man found him when he awoke and told him that Duo was thankful for his help.
Although Mega Man 8 was released on the Sega Saturn shortly after being released on the Sony PlayStation, the Saturn version was not identical to the PlayStation version. The differences are:
- A Bonus Mode was included, which includes official and fan artwork, voice test, music test, and a secret animation test for the FMVs. Of note, the voice test includes some unused vocal samples, including an unused line by Frost Man, Dr. Light, and Mega Man saying "Metal Heroes" (used in the Japanese version). By holding L and R and pressing start to get in there, some additional options are available. Bonus Mode replaces the "Game Information" option from the Japanese PlayStation version, which showed previews of the then-upcoming Rockman: Battle & Chase and Super Adventure Rockman.
- There are a few additional enemies added in the stages (for example, the game's first two enemies are Metalls).
- Water has an additional morphing ripple effect, giving the scenery and background an animated wave motion.
- A loud red siren immediately flashes when Mega Man enters the derelict base of Duo's mini-stage. It stops during boss fights.
- Cut Man (from Mega Man 1) and Wood Man (from Mega Man 2), who appeared as cameos among the crowd of Robot Masters at the end of the opening animation, make appearances in Duo's mini-stage and Search Man's stage, respectively. Cut Man is an optional encounter, while Wood Man is a mandatory mini-boss. Defeating them earns Mega Man two Bolts that are otherwise lying in the open in the PlayStation version. Once their Bolt is collected, they cannot be challenged again. (On a side note, Cut Man and Wood Man are thought to be the apparent stolen Robot Masters that were in two broken display cases seen in the background of the Robot Museum stage in Mega Man 7.)
- The music is slightly different in the Saturn version. Two notable examples are Aqua Man's Stage, which is moodier and has a wider variety of instruments, and Tengu Man's Stage, the only stage in the game which had an entirely different tune. Also, because of Cut Man and Wood Man's appearances, their original stage themes are played in the Saturn version when players battle them; both are remixed to match the sound of the rest of the music. The Saturn version uses PCM encoded audio, while the PlayStation version uses the internal MIDI system of the console.
- The full-motion videos in the Saturn version are compressed using Cinepak compression, which causes artifacting and slight blockiness, whereas the PlayStation uses its native MPEG.
Intro Stage boss:
|DWN-057||Tengu Man||Tornado Hold||Ice Wave|
|DWN-058||Astro Man||Astro Crush||Homing Sniper|
|DWN-059||Sword Man||Flame Sword||Water Balloon|
|DWN-060||Clown Man||Thunder Claw||Tornado Hold|
|DWN-061||Search Man||Homing Sniper||Flame Sword|
|DWN-062||Frost Man||Ice Wave||Flash Bomb|
|DWN-063||Grenade Man||Flash Bomb||Thunder Claw|
|DWN-064||Aqua Man||Water Balloon||Astro Crush|
Mid Stage Boss:
Wily Castle bosses:
- List of Mega Man 8 enemies
- Mega Man 8 Walkthrough
- Mega Man 8 Damage Data Chart
- Mega Man 8 Script
- Rockman 8 Original Soundtrack
- Rockman 8 (manga)
- Rockman 8 Famicom
- This game was released after Mega Man 2: The Power Fighters, but it is set before it as shown in Duo's ending.
- The opening FMV of the game shows some bosses from previous games; in one sequence, the Robot Masters that appear are in the order of the game they appear in (1-7): Guts Man, Quick Man, Snake Man, Pharaoh Man, Charge Man, Tomahawk Man, and Shade Man.
- In the boss character contest of this game, Capcom said three of the six robots (not including Tengu Man and Astro Man) to be chosen to appear in the game had to have a specific appearance, being one with a sword and separable body, one with two heads, and one with long extendable arms.
- This game marks Duo's first (chronological) appearance.
- This is the first (and only) numbered game in the classic Mega Man series to feature FMVs and voice acting.
- This is the only game since the first Mega Man (without counting spin-offs) to not include Energy Tanks.
- Starting with this game, Mega Man was no longer able to use the Super Adapter. However, Bass was still able to use it.
- This is the first game where Capcom didn't try to "Americanize" the boxart (excluding Mega Man 6, which wasn't published in the U.S. by Capcom, themselves). Also, this is the first Mega Man game to use the Japanese logo in other countries.
- This is the second numbered game where Mega Man could swim, the first game being Mega Man 3 for DOS.
- As with Mega Man X4, the game is often poked fun at for its voice acting in the U.S. and European releases, particularly Dr. Light who speaks with an apparent speech impediment, infamously pronouncing Doctor Wily as "Doctah Wahwee". His voice happens to sound very similar to Elmer Fudd's.
- As with Mega Man 7, there's a part in this game that contains a typo in Mega Man's speech, as well. After Bass is defeated, he'll say, "Bass, why you don't understand?", when it should have been, "Bass, why don't you understand?"
- There's also a typo in Proto Man's speech after the Duo intermission stage, where he'll say, "What happend?"
- Both of these typos were later corrected when the game was re-released in 2017 as part of Mega Man Legacy Collection 2.
- This is notably the only Mega Man game where Dr. Wily doesn't try to trick Mega Man when defeated by feigning guilt. In fact, his reaction when the Evil Energy tries to corrupt Mega Man implies that he was not planning on using the Evil Energy to attack Mega Man to cover his escape, and that he probably had no intention of tricking Mega Man.
- The Saturn version is thought to be the original version or at least closer to the original vision of the game - according to interviews, it was intended to be a Sega Saturn game all along, but Sony allegedly demanded the game be released on their system.
- The music that plays in Dr. Wily's fourth stage is a remix of the pre-boss fight music in the game.
- The enemy that loses the fight to Duo at the start of Mega Man 8 doesn't have a name. His design appears in R20 Rockman & Rockman X Official Complete Works. The Archie Comics Mega Man series would later give him the name of Trio.
- This is the first game in the Classic series not to have artwork for the Special Weapons.
- In the Sega Saturn version, Wood Man appears as a boss in Search Man's stage and Cut Man appears as an optional boss in the Mid-Stage.
- This marks the second classic Mega Man title in which fighting the Robot Masters goes through a unique canon (with the first being Mega Man 7); rather than fighting the eight bosses in a row in accordance to their weaknesses, Mega Man must fight them in two sets of four.
- This is the only numbered game in the Mega Man Classic series that is not on a Nintendo system (excluding Mega Man: Anniversary Collection and Mega Man Legacy Collection 2). It is also the only numbered game in the Mega Man Classic series that is available on a Sega system (besides the first three games that were re-released on the Sega Genesis as Mega Man: The Wily Wars).
- This is the first Mega Man game to show the amount of available shots for a Special Weapon in numbers (as opposed to the traditional Weapon Energy bars). The next game in the Mega Man franchise to do this would be Mega Man X4.
- There were a total of 110,000 boss character submissions for this game, some of which were shown during the ending credits.
- There is a bootleg version of Rockman 8 for the Game Boy.