cool idea! I like the idea of having the fan blow back the bullets. However, all I really had to do was hold down the LMB and just wait for them to shoot, so that kinda took any stragety or fun away from the game. I was make a "cool down" timer (pun not intentional) to the fan so you can't use it after a set period of time and have to wait for it to cool down before using it again. It's a bit bugging with the UI and something enemies wouldn't come out all the way, but definitely has potential so good job!
I'd appreciate if you could play/rate my game as well! :)