The mouse sensitivity definitely needs to be turned down about 20 notches (or at least add an option to the settings menu), that was about the only thing preventing me from wanting to keep playing your game to the end, The auto fire was pretty slow, and I felt like it would've been nicer to have it go faster, but that was mainly at the beginning and I definitely minded it less as I got further,
The music is soooo nice and relaxing, it fits perfectly and helps a lot to cut the tension that would otherwise come with a frustration game like this. And all the juiciness was really well done too, nice job =)