Best Batman game available. But that's not saying much.
The graphics are pretty average for the NES. They are pretty detailed and overall pretty good but they are too dark. I know this is Batman, but a little more color wouldn't have hurt anyone. The soundtrack is pretty good. It doesn't raise the bar of in game music but it's still pretty good.
The gameplay is just lke you'd expect. Walk around jumping, punching and doing cool Batman moves. There aren't too many moves to pull off but it's not like it's supposed to be a fighter. The game isn't too long and there aren't very many reasons to replay except it is a pretty fun game. It's not hard either. It's ranks on the easy side.
Overall, if you're a fan of Batman this is worth it. If you're a fan of platformers, this is worth it but if you're not a fan of so many platformers being on NES then you may want to avoid this.