Braid

Braid is the most innovative game I think I've ever seen. I started playing it last night and when I looked at the clock I couldn't believe it was 2AM. It's that engrossing. It's a visual feast, has a mysterious and engaging plot, and is just plain fun. Time is used not only as part of the narrative, but also part of the game play. You've got to play it to see what I mean. I haven't had this much fun since Portal.

I wish I had made this game.

I offer one hint-- Do NOT check out the walkthroughs on YouTube. It'll spoil the best plot twist since (again) Portal. If it seems there is a puzzle piece you can't reach, just keep in mind that the game has a non-linear story. You won't "finish" each level in turn as you would, say, Donkey Kong. OK, you can finish each level in sequence. Still, be careful about looking for clues. I made the mistake of poking around and it spoiled the ending for me.