Marvel Heroes is a free-to-play massively multiplayer online action role-playing video game developed by Gazillion Entertainment and Secret Identity Studios. The game was then officially launched on June 4, 2013, on Microsoft Windows. The plot revolves around heroes and villains, with the main antagonist as Doctor Doom, in various conflicts. Marvel Heroes features more than 100 characters from the Marvel Universe. Players can choose from a large and diverse cast of superheroes and villains.