Future Fight is another very popular Marvel game. This one is an action RPG. Like most freemium Marvel games, this one also includes character collecting mechanics. Each character is upgradeable.
Players can get both super heroes and villains if they prefer. It’s a bit of a fan service dump and cash grab. At least this one is kind of fun, though. Just try to be patient when it comes to the freemium stuff and you should have a decent time.