Yeah it's not as complicated as it sounds. Basically for the upcoming X-Men: Battle of the Atom storyline/event, Marvel is releasing a video game tie-in. In the game you'll pick characters from across time and fight some of the X-Men's biggest villains! You can also collect cards to upgrade your dudes. It sounds like micro-transactions at their finest. It's going to be released on the big two mobile platforms since that's all anyone cares about apparently. Since the storyline doesn't begin until September, I'd say it's a safe bet that the game will hit sometime around then as well. Here's the trailer to get you hyped on it!
Via USA Today