Pretty good concept and a solid little game. My only issue is that the difficulty is a little low and lies more in getting a good bounce with the grenade than anything. It felt more trial and error than skill in those instances, and the lack of a way to cancel a grenade didn't help. It wound up being kinda frustrating having to teleport back two or three times just because you got a wild bounce. My suggestion would be to add in some kind of cancel button, or to separate the grenade and activation buttons to allow you to retry a shot without having to jump back up.
The other side of the coin is that the enemies offer practically no increase in difficulty. If they were able to kill you in one hit, I would've only died once during the entire game. They feel kind of vestigial if they don't pose a threat. Maybe an enemy with a ranged attack would shake things up?