It's a bit barebone graphically, but it's to be expected for one man teams. You generally can only focus on a couple of aspects and the gameplay was one of those here. I can definitely see a game here by making this all a bit faster and maybe add some form of strafe jumping.
As for the controls, I'd say you should poll for the reload button only on key down and maybe have a cooldown ;) You can keep R pressed and never run out of ammo.
Nice one !