Gamespot got the score right on this game. The gameplay tops the second game, but the online is a disappointment.

User Rating: 8.5 | Marvel vs. Capcom 3: Fate of Two Worlds X360
The 3rd game finally came out and we were all pumped, we ignored that most of our favorite people werent returning in this game and it turned out to be actually pretty good. The gameplay is more realistic and there doesnt seem to be as much spamming with assist like on the second game. The main thing that im sure everyone is disappointed with is the online. You arent even allowed to watch others fight, you have to stay in the lobby and watch their health bars hop up and down. Its quite sad that the DC before this game could do that but yet this one could not. Other things that could be mentioned is some characters are a bit over powered. Like Captain America. He almost takes no damage when he blocks unlike many other people, and his hits are like the Hulk. Plus some peopl may get frustrated with the character switch. Its now as easy as the first 2. But overall this is a good game, but Capcom could have done better, especially with the online. Its a good game, go buy it. But Capcom still has some things to fix out.