is available now on iOS devices for $2.99. The 1992 beat-em-up classic supports drop-in multiplayer for up to four players, along with Openfeint (Leaderboard and Achievements), Game Center and Facebook Connect for publishing scores. The game appears to be the full experience, including the full campaign and all six playable X-Men (Cyclops, Colossus, Wolverine, Storm, Nightcrawler or Dazzler).
A word of warning: the game is designed for the 3rd generation iPod touch, the iPads, iPhone 3GS and iPhone 4. Although the requirement is mentioned in the press release, the App Store doesn't appear to note it. Reviews of the game in the store complain about it not working on the iPhone 3G or any 2nd generation devices.