Awesome take on the theme! The small, red skeletons gave me a real spook when I first saw them rushing towards me xD
Audio would be an awesome addition when the rating period is over. If the red skeletons already got my blood pumping, then audio would make it even more exciting.
Also, I noticed some of your green skeletons get stuck on the walls when they ran into them. Some of them were able to get themselves out but others remained stuck!
Overall, congrats on your first full game! I had a lot of fun :)