Thanks! If you see on the right, the amount of time crystals is how many times you have to run through and defeat him (as that's how many times he can rewind the level.) The differing difficulties have differing time amounts and time crystals. The gun also is supposed to be a sort of last-resort use, so you'll have to find your way around some obstacles at times in the quickest way possibly to beat the time. Hopefully this clears things up. Sorry you had a bad experience with it.
Viewing post in Villain REWIND - Unity Demo jam comments
Don't get me wrong, the game was fun to play, but only for a short while because it eventually got a bit repetitive to just run towards the button, thanks for clearing the gun up, maybe it could be replaced with something like a hammer to indicate that it's supposed to break the blocks? At first I thought there would be enemies! Anyways good job