Just finished the game today. It was actually pretty fun, even more so than the X-Men Legends games. A little too short at times, but otherwise a blast.
The gameplay was almost exactly like XML2, with a few changes. The health and energy items are gone, replaced with little red and blue orbs that drop from smashed objects or enemies. The missions are much longer; the prologue mission alone takes nearly three times as long as the one in XML2, and actually bothers to include some actual boss fights. The story itself is semi-interesting, although the promised plot branching never came to be; instead, the ending changes depending on a good number of choices made during gameplay.
The only problems I had with the game were the pathetic AI, especially for the other party members (still has nightmares about the Galactus level), a lot of annoyingly cheap bosses, sometimes vague objectives, and an extremely annoying sidequest that spans half the game and leads to nothing. Still, it’s a pretty good game, and does well to allieve my dissapointment with MKA.