Braid is a fun and overall very well made game. The time manipulation idea is not novel in itself and has been featured in games released before it, but arguably Braid uses it better than any other similar game I can think of. In a vacuum, Braid's gameplay feels shallow if compared to more gameplay focused puzzle platformers like Umihara Kawase and Lode Runner. The story ties in to the gameplay in a very cool way, but it's told in a pretentious style that can be off putting to a lot of people, myself included. For people who like 2D platformers and puzzle games, this is an absolute must play.
