"Shared-world Shooter" is Bungie's official term. And any game that maxes out at 12 players at any given time will, by definition, [i]never[/i] be a [i]Massively-Multiplayer[/i] Online game. It's an FPS, with light RPG elements, even [i]lighter[/i] MMO elements, and a butt-ton of loot. "First-Person Looter" works, too, haha.