Marvel Super Hero Squad features super-deformed cartoon version of Marvel Comics characters, as seen in the Marvel Super Hero Squad toy line and television show. The game has two modes. During adventure mode two characters (one character in the DS version) fight through a level by defeating waves of enemies. The game features on-the-fly character swapping, similar to the Lego Star Wars games, as well as drop-in, drop-out cooperative gameplay, with the AI playing the unused character during single player. Battle mode is a free-for-all fighting mode, similar to the Super Smash Bros series. Players defeat enemies by depleting their health or knocking them out of the arena.
Source: Wikipedia, "Marvel Super Hero Squad (video game)", available under the CC-BY-SA License.