Actually, FYI there the original copies of the game did indeed star Spider-Man and Batman, but if I recall later there was a huge thing with Marvel & DC and Sega was forced to simply make them off-clones of the two popular super-hero\'s. Therefor, the later copies didn\'t have Spider-Man and Batman in the sense, their logo was the main thing missing.
I may be wrong, but I remember reading that on Classicgaming, I think. I\'m sure Altered could step in and clear this up.
As for Shinobi - my further impressions are this. Damn, this game gets frickin\' hard real fast, however it isn\'t hard enough to make you quit. It only encourages you to get better and better . Run on the wall, lock on enemy, jump , dash, hit, jump, jump, dash to wall..run on wall. It becomes almost second nature and when you do a succesful "tate" attack among everything, you look at the screen amazed that you actually pulled that off . In simple, this game is amazing and probably the best stuff Sega has put out since it went third party.