One of the best TV cartoons out there (NOT the current TMNT) finds itself in one of the most difficult games for the NES
Now the gameplay is simple....you walk around and battle foes....it gets complex when you are walking....walking....walking around a stupid city where you can't find where you're supposed to go! The difficulty in this game is incredibly insane. I have tried it without the Game Genie and could not get past the city stage. I thought StarTropics was a game you couldn't beat unless you had the Game Genie, but I beat it without it...but THIS game is VERY VERY VERY difficult! If you want a challenge, I recommend this game.
The music is pretty good for an early-generation NES game. It has the TMNT snipets and the cutscene music is well thought out.
The graphics I think are very good. There are times where there is slowdown, ESPECIALLY in the water stage (area 2). If you aren't careful, you'll get shocked by even barely brushing against the seaweed. The detail of the side scrolling is very good, along with the design of the city...at least when you are wandering around an impossible city you get good scenery.
Overall, if the game weren't so god-blessed difficult, it would be a great game. But we can't change the past now can we. TMNT II: The Arcade Game is a difficult one as well, but not as bad as the first one. I could only beat TMNT II in co-op mode with a friend without the Game Genie.
If you've never played this game, it's worth a shot. I do not discourage not playing this game, but no matter if you are a novice or an expert at game, this game's difficulty will piss you off to no end!