Congrats on putting this out!The visual stylization look great, I love the inky look you did for the sprites.
Ambience category represents both visual and audio. There are plenty of royalty free music out there for your usage, you can find one and implement it into your game in about 30 mins. Don't let the lack of music bring down your ambience points for your game!
Gameplay is interesting. I think it can turn into something great with more time in the oven. Thanks for making this!