Visuals were really good! I liked the overall premise (especially given the theme) but in execution it fell a little short for me. It's so easy to die or run out of bullets (and be therefore unable to progress) that found myself playing extremely cautiously. Especially once I got to the end the first time and realized I'd probably need bullets to fight (spoiler alert): the boss.
I think this could have been fixed with some tweaks to jumping. Perhaps having the ability to shoot down in mid-air to jump higher and also shoot a bullet down?
That being said, really strong premise and really impressive work for 9 hours!