Mega Man: Wily Wars features remakes of Mega Man, Mega Man 2, and Mega Man 3, with improved graphics; however, it also features Wily Tower, a new mode in which Mega Man may use any weapon he wants and defeat new Robot Masters from the Genesis Unit.
Universally, there were two changes:
- Mega Man is always buoyant in the water.
Although the game is a decent port, many things were changed for various amounts of reasons.
The boss select screen now has full portraits of the Robot Masters instead of their sprites alone.
Robot Masters were changed:
- Bomb Man's move pattern has more jumps.
- Cut Man has a higher defence to Mega Buster.
- Fire Man shoots one Fire Storm at a time. This was probably added to prevent any slowdown from happening during the fight.
- Ice Man lags, but this is possibly from the aforementioned sprites issues.
Some layouts were changed, but in slight ways:
- There are lesser amounts of Suzies in Cut Man's stage.
- The strangely-placed continue spot in Elec Man's stage on the edge of a platform at the start was removed.
- The extra life in Guts Man's stage was moved to a lower area and the pitfall below was closer, making it easier to cross over to the life.
- The fake pitfall in Fire Man's stage is now a real one, and if Mega Man jumps in it, he falls to the next part.
- Wily stage 1 has flying machines which go over the edges.
Two weapons were changed:
- Super Arm has a much higher arc when throwing Guts Blocks across the screen.
- Magnet Beam will extend out in just parts, making it much slower.
Glitches were fixed, with exception to the glitch in which Mega Man loses a life on spikes when hit by an enemy attack:
- The Select button glitch in which one enemy could be hit over and over by hitting the Select button rapidly was taken out. This was effortlessly removed as the Genesis has no Select button, nor a pause screen except for weapon choice.
- Items do not re-spawn when leaving the screens.
Mega Man 2
Like Mega Man, Mega Man 2 is also a decent port, but it also had changes done.
In all versions of the game, there is no difficulty selection. This was originally only in the Japanese game, but the European and American versions do not get the option for "Easy" difficulty now
Layouts were changed, but in slight forms:
- The clouds in Air Man's stage which have the enemies on it are spread out.
- The middle of Flash Man's boss battle is not as deep as before.
- There is a wall in Wily stage 1 which stops the slider enemy from flying off screen, rendering him a threat.
- The gap in which Mega Man had to use the Item-1 over and over was widened out.
Robot Master attributes were altered slightly:
- Air Man goes closer to the wall, meaning Mega Man cannot shoot behind.
- Flash Man has a much higher defence to Mega Buster.
Some weapons were changed slightly:
- Item-3 moves a lot slower, but not from slowdowns.