I think there's some elegant design here, however I think the best playstyle is to just constantly rewind in short bursts, so there might need to be an additional mechanic that punishes a work around like that.
I like that a lot of the mechanics are double edged. You need to rewind to give yourself more time, but rewinding temporarily creates a new danger. You need to hit enemies with the bomb, but the only way to do that is to stop rewinding and hit the bomb yourself. Interesting stuff with lots of potential.