Check out this awesome hack for Megaman 2, it’s called Wily’s Conquest. It features totally new levels, new enemies alongside some tweaks like speed, energy bar and more.
Overall this hack’s worth getting, there’s some problems with it though which get demonstrated in the video. Take the battle with Flashman for example, it only uses 1 door for entrance into the battle and the 2nd door is hidden all the way to the right. Go close to it and you’ll glitch to a room with nothing in it.