I think most people would agree that TMNT on the NES wasn't a "good" game, mostly because of the extremely poor difficulty balancing, but it certainly could've been a lot worse. At least the game had awesome music, fast gameplay, powerups, and could actually be completed. TMNT for DOS however... This is a great example of how NOT to port your game. I think the trouble ultimately was that they gave too few people too little time to port the game to multiple computers, and when the order came to release the game, the DOS version simply wasn't ready. The entire game has an unfinished feel (especially from the end of Level 3 onward) and can't be beaten without cheating.