Man... I wish you had more time to polish this. The fact that you went 3D is in itself impressive, and you nailed the fun spooky Halloween atmosphere with solid sound and visuals. I'm really fond of the core concept. Placing towers also defines the path for the creep (trick-or-treaters in this case), I don't think I saw this before.
Not a fan of the recharge system tho :D Towers burning fuel at a fixed rate regardless of activity felt frustrating. it would work better if they only consumed candy when actually firing. That small change would make resource management much more engaging.
I'd love to see this expanded into a fully fledged game with bigger levels and more tower variety. Great foundation keep building on it!