Ahhhh duuuude.
First off, love the game. Seriously deserves the 10/10.
But you gotta watch out for one thing! When two enemies are coming (different groups), and one is on a route that is closer to the castle, you have to make it so the towers will be attacking that one. I just lost 'cuz of that, so I figured I'd tell you. :P
The only other improvement would be different sound tracks for the game. I can't believe you made this huge game with only 730k, that's nothing!
Nice job and I hope to see a #2. Or atleast an updated .swf with enemy priority rates. :P