That's a really fun game (even though I couldn't pass level 4). I like the look of the game and the rewinding ability. But I found some small "bugs/problems" : if you click right next to the retry button the game is also restarting and the character is shooting at the button if you restart the level, if you stand on a button while holding a box after a few seconds the button isn't pressed down anymore, in level 4 the bullets you're shooting go through the ground and are only destroyed if they hit the box or the flag.
Apart from that everything worked fine and I really liked the game :)