"Marvel Heroes is a free-to-play massively multiplayer online action role-playing video game developed by Gazillion Entertainment and Secret Identity Studios. Characters such as Iron Man, Captain America, Deadpool and Wolverine serve as characters that players can unlock in the game... The game was then officially launched on June 4, 2013... The plot revolves around villains, with the main antagonist as Doctor Doom, and heroes in various conflicts."
Credit - Wikipedia
The game is getting updated today to Marvel Heroes 2015, which brings some massive updates. If you have played it, you might recognize some ideas being used in DI 2.0 (Team-Ups, Costumes, etc.) I've been playing since around March, and I find it really fun. Anyone else play?
note: I wasn't sure whether this would go into Disney, so I put it here because LEGO Marvel is also here.
Massively Joystiq is giving out codes for a free random hero here. To redeem, go to marvelheroes.com, login, go to your profile and there should be a "redeem key" option on the right.