Stay alive for 10 minutes using your towers to defend yourself.
Nice game. There are some things I would like to see improved. You can build while paused. The enemies behave kind of weird sometimes and bump into walls. Upgrading damage would be good. When you can't upgrade range, rate, or rotate speed anymore, the text with cost should go away. Better visuals and sound effects are what you want for your next games. Overall, I like it, 3/5.