Acclaim managed to make plenty of lackluster video games using popular Marvel licenses (X-Men, Spider-Man, Iron Man, and let's not forget that Fantastic Four game for the PS1), but to this day Sega is the only company to make a great X-Men game (in fact they made two; this game and it's sequel X-Men 2: The Clone Wars).  X-Men manages to catch the spirit of the comic  allowing you play as Wolverine, Cyclops, Nightcrawler, and Gambit while getting assistance from Iceman, Storm, Rogue, Archangel, and Jean Grey.  You go through a number of huge levels, ranging from the Savage Land to a Shi'ar ship to Excalibur's castle to a ravaged Sentinel filled future to Asteroid M where you confront Magneto.  You are thrown against hordes of generic looking enemies, but X-Men is surprisingly difficult and features some great boss battles (including Juggernaut, Deathbird, Sabretooth, Ahab, and finally Magneto among others) and the game effectively uses each character's different mutant powers such as Wolvie's berserker attack and Gambit's kinetic laced cards.  The graphics are sharp, colorful, and surprisingly full of detail, while the controls are easy enough to pick up.  All in all, this is one of the best Marvel licensed 16-bit games ever, but it would only be topped by it's sequel X-Men 2: The Clone Wars.