guys, all u have to do is make 1 mega tower, composed of 3 sniper towers and 1 machine gun, then just put 2 speed boosters, and as many damage boosters as possible, well, for all the medium levels. It's the fastest way.
that was by togenji: doesnt work the towers dont have enough range until the sniper upgrades and for those of you complaing bout splitters dont if they didnt jump over your towers then they would get stuck in the towers and then the game will crash