While it's possibly too-informed from Sands of Time, I found Braid to be a fun, unpretentious time-travel-mechanic game. Quite possibly the best (though, certainly not the most informed or most perceptive) review of the game is by Soulja Boy:
http://www.youtube.com/watch?v=xSXofLK5hFQ
and I know what you're thinking: no, that wasn't a reference to Nietzsche, OR Montaigne. But his response and childlike fascination with the sheer simplicity of the conceit is something that, I think, speaks to all of us: the basic desire to control the effects of time. Indeed, it's that which is its strongest quality: the game as a whole is as simple as its device. Sands of Time, while probably the better game, requires more finesse, more effort (though, to paraphrase Dr. Johnson, that which is played without effort is also played without pleasure). To me, Braid is the so-called casual game that I might give to Roger Ebert or someone newly interested in the medium; it's not narrative, and it's not structured (and in light of those, it's more avant-garde than it is anything else), but I think it's pretty cool.