Way to much lag, and boss's are maybe to strong... im struggling with the head... Money system is crap. I think this game has potential, just a thick headed designer/programmer.
Stuff the last level, Its impossible. If you dont want to starve yourself of energy more than usual, you cant build defenses in time. If you do, you cant build defenses in time. Lose lose Scenario for player.
AI Cheats. They have infinte amount of money. I tried just making towers and waiting for them to spend all there money, cause they go shredded by my turrets, but they never stopped making units!