Really, really cool and fun game! Love the polish on it, as well! Camera shakes and particles! Beautiful!

Great idea. But in this kind of game I strongly feel that it need strength indicator to give player some kind of reference.

I agree strongly with althaj. The rewind feature should have been the core of the game, but it felt pointless and useless, I never felt I had a good handle on it at all and never used it to beat any levels. It just boiled down to an Angry Birds-like little physics game.

I think each grenade should have had a timer on it, a bar or numbers ticking down, color changing from black to red until it explodes, something. 

Very good physics game! I didn't like the rewind feature though, it felt really useless, I used it only to time the explosions (when a grenade was rolling away from the target).
Also it would help if the health bars didn't rotate with the targets.