Pretty nice integration of the theme, and really good visuals imo. I like the music, even if it's a bit repetitive, but have some reserve on the sfx. It's more of a personnal preference but I'm not a huge fan of the 8bit vibe. They are also pretty loud, to they tend to hurt the ears and makes you want to lower the volume. I love the bouncing bullets sounds tho, it's super cute haha.
Overall pretty good game, that could just use some work on the sound design and mixing :)