Level 16 - Worthy Plunder

After you beat the Asp Boss, you can re-run the level with standard enemies on the same map.

The principal of applying the longest possible path to the enemy applies on this level so pay attention to the paths and how the change when you place towers.

One neat trick is to place boulders making the monsters go one way, then removing the boulders and placing them somewhere else, making them go round in circles.