An excellent early entry in the comic book - videogame genre.
Xmen for the Sega Genesis is an excellant title which, in my opinion, deserves a place in XBLA.
Sabotage in the X-men's mansion leaves Wolverine, Gambit, Storm, Cyclops and Nightcrawler trapped inside their hologram training program. Along the way, they'll face such classic villains as Juggernaut, Sabertooth, Apocalypse, Mojo and Magneto. Lots of fun levels with little repetition and a decent choice of playable characters provides a fun experience.
X-men delivers decent controls and gameplay with excellent graphics for the time. Being able to play as four different characters each with their own special moves maintains the replay value. I think the available characters were good choices. My personal favorite is NightCrawler.
Overall, this game offers a fun experience with a few innovative surprises. For instance, On Mojo's level, you have to "reset the computer" in order to escape from the holographically simulated level. After defeating Mojo, you actually had to push the reset button on your Genesis to advance to the next level.