We got our first look at Fortnite this week, as Epic finally took the wraps off its free-to-play game. But what is it? A new video features Epic talking about the story, the mechanics, and why it chose to go F2P for this one.

The Game Informer video lays out the details. The monsters that attack at night play into the game's story, which involves closing rifts caused by some nebulous threat known as "the Storm." You'll set up your own home base, while constantly pushing out into the field to find rifts and close them. Though the building tools are accessible anywhere, letting you craft some make-shift defenses in a battle zone, they're really expressed most elegantly back at your home base.

"It's a great way to have a conversation with players because they're not obligated to like it, so we have to do our jobs," said producer Roger Collum. "We have to be awesome game creators to say, 'it's worth your time to play this game.' And I think we've done that." He stresses that the goal is to make it both free and fair, and so they feel confident that the fans will reward their work by buying an item or two if they like it.