There are 21 playable characters featured in Marvel Super Hero Squad. Here's the fill list...

Abomination

A.I.M. Agent

Captain America

Dr. Doom

Dynamo

Falcon

Hulk

Invisible Woman

Iron Man

Juggernaut

Magneto

Mole Man

Ms. Marvel

Nightcrawler

Sabertooth 

Silver Surfer

Spider-Man

Storm

The Thing

Thor

Wolverine

On the Nintendo Wii version, you’ll also be able to play as Black Suit Spider-Man or Black Suit Captain America if you pre-order the game. Click here to find out more and pre-order Marvel Super Hero Squad.