Overview
This simple exploit can help you beating many levels.
Not enough firepower?
In many levels, you can create two different entrances for your enemies. When you block one entrance (preferably with a cheap cannon tower), the enemies will always head for the other entrance. But when you sell your tower and place one on the other entrance, all enemies will turn around and march towards the first entrance. So you can trap all units carrying sheeps within the space between the two entrances. Just build a cannon tower, when they reach your entrance and sell the other one. By using cannon towers, you’ll only lose 30 $ per tower – which is nothing.
Examples:
