Done in 48 seconds on my 3rd try (12 left on the clock).
With all the comment saying this was hard I thought it would definitely be impossible for me, but my weird ‘if it’s easy for other people it’s hard for me and sometimes vice versa’ kicked in I guess. – In short, I’m not sure what made this work/enjoyable for me, but you pulled it off.
In particular: I think the ‘swing the mouse to flip the barrel’ was an inspired bit of UI!
Could’ve used some sound! If you already know this, I hope this doesn’t sound condescending, but if you don’t: I think I’ve added SFX to games in less than 8 minutes :-p … just search for ‘sound effect generator’ or ‘sfxr’, ‘bfxr’, ‘jsfxr’ and you’ll find a dozen.
Lastly, as an aside, if you think about it, it’s kind of strange how a game that features a gun this prominently, ends up being less violent than most big budget games, as here you’re just shooting targets.