Well, I made this game a while ago as my first flash game. I never got around to adding the stuff that I wanted to add such as upgrades, different enemies, customizable turret, and a lot more.
I'm sure I will add that stuff sometime though, until then, have fun with this!
EDIT: It seems everyone really thinks I should update, so I guess I could work on it again. :D
Thanks for sharing your thoughts and giving me the extra boost that will help me get this done!