From Gameplayer... "The genius of Super Mario Galaxy is that its basic game design solves every problem that's ever existed with a platform or adventure game. Until now, your experience in a game world has always had to make sense in strictly architectural terms. Every corridor and every room has had to fit together like a giant jigsaw puzzle. Sure, levels need to seal you in to be coherent, but it always seems jarring when you can't unlock certain doors. The more realistically games suck us in with environments from the real world, the more acutely we're aware they're fake."