Revolver spinning is a great application of the theme! I really liked keeping track of which bullet I was shooting, and so which ones to shoot towards enemies and which ones to shoot away.
I really didn't like having empty chambers. It felt like it messed with the pacing. I would start with all chambers filled with normal bullets.
It looks like you were going for a pirate theme, I'd lean into that more. Make the background a pirate ship, make the enemies nautical, that sort of thing.
Great game!