it's actually a super robot disguised as a golf cart (or possibly a golf cart disguised as a super robot)
whatever it is, what you're doing is you just have like a normal-ass 6 shot gate-loading revolver and you're shooting and reloading at a manic pace in order to avenge your father (probably)
if you look closely you can see the player discarding shells every 6 shots and then reloading VERY QUICKLY