This hack fixes numerous bugs in the NES game Cheetahmen II. The game is infamous for having several bugs that prevent players from completing the game.

From the developer:

"ApeMan, the boss at the fourth level, disappears if he leaves the screen, and if you beat him, it also disappears, so you get stuck at that level and it's impossible to go through the last two levels unless you experience a very rare glitch when turning on the game. Level two boss can disappear in some circumstances. There's a hacked version of the ROM that offers only the last two levels, but it's also very buggy. The final boss disappears too and it's impossible to finish the game. Now, all of that is fixed and the game can be completed with no problems. No more enemies disappearing, all levels load correctly, and no annoying level number glitch (levels 4, 5 and 6 were called level 3). I made some palette and graphic modifications, to fix some elements that looked ugly. Also, I fixed some spelling errors in the intro."