Whenever I think of X-Men, the first thing that comes to mind is the epic intro sequence for the animated series. (Seriously, go look it up if you've forgotten about it.) The second thing that comes to mind are the endless quarters I spent at the skating rink playing the X-Men arcade game with three of my less athletically-inclined friends. Having known an official X-Men port was in the Market, I finally took the plunge and tried it out.
Diving right into the gameplay, it's just as good as I remember it, sans physical joystick and arcade buttons. The replacements for those are all virtual, as you'd expect, and are prominently displayed on the bottom-left and right corners of the screen. I've heard some people complain the buttons are too close together on the phone version, but I didn't experience that and I definitely didn't see that issue on a tablet.
Performance-wise, the game performs well. Period. It's an old 1992 game, so it should run well, and it does. The cheesy opening video goes quickly, there weren't any force closes, and not one framerate skip or stutter to speak of. Simply put, it's just as good as the arcade version, except this one fits in your pocket (or backpack).
My only complaint is that the virtual joystick isn't quite as responsive as I'd like it to be, which caused me to get straight pwned a couple of times. I only really saw the issue when needing to do a quick 180, but still, when Sentinels are coming down on you from all sides, you need cat-like reflexes to put them in their place.
X-Men does support four-player multiplayer, as long as all the players are on the same Wifi network, so yes, you can relive your glory days all over again.
X-Men is 99 cents in the Android Market. Download links are after the break.