Just a short reminder, showcased this game some time ago… This game launched 4 Jun 2013, and you can download the client directly from the Steam Client..

Get it on Steam

or at the official site…

Marvel Heroes is a free-to-play MMO Action RPG created by David Brevik, the visionary behind Diablo.

Marvel Heroes combines core gameplay elements of Diablo with the expansive library of heroes from the Marvel Universe, including all the Avengers. Collect and play as your favorite Marvel Super Heroes including Iron Man, Thor, Black Widow, Captain America, Wolverine, Hulk and many others. Team up online with friends and customize your heroes with a library of spectacular powers, costumes, and gear. Adventure through the Marvel Universe and stop Doctor Doom from devastating the world with the power of the Cosmic Cube. Features a world-spanning story crafted by comic book super-scribe Brian Michael Bendis.