Zoom And Boom

I could use a little feedback on the game so far, please give it a try. (Windows exe only right now) There are 3 levels with 2 waves each right now.

http://www.scottshaver2000.com/blitz/zoomandboom/zoomandboom.zip

The tutorial I'm writing for it:

http://www.scottshaver2000.com/blitz/zoomandboom/tutorial/index.html