hey i had goten to the green cannon and then i lost but the cannon ball stayed on the screen and when i played it again the cannon ball kept following me around. I mean seriously
i found a way to be invincible.
on the 4th stage build 4 double turetts and then move on to the 5th stage don't put on any new turetts and you will be invincible without hitting the enemies base so you can play as long as you want!
 "Tangerine Panic!"){kind=icon}
 "You Have To Burn The Rope"){kind=icon}
 "Bubble Tanks 2"){kind=icon}
 "Streamline"){kind=icon}
 "Protector"){kind=icon}
 "Age of War"){kind=icon}
 "Feudalism"){kind=icon}
 "light-Bot"){kind=icon}
 "Vector Runner"){kind=icon}
 "Aether"){kind=icon}