This tower defence game works differently from traditional TD games. You are in charge of sending creeps out onto the field, and ensure that they reach the exit. The computer's job is to build towers in order to stop the creeps you send out, from reaching the exit. You can send out stronger creeps and alter the directions of the arrows to form a path from the entrances to the exit. To unlock the next level, you need to ensure that the required number of creeps reach the exit.