Paper Defense is a unique tower defense game in which you can expand your base by building walls. Prevent enemies from destroying your base by attaching turrets to the walls and sending out ground units to attack them. Each type of wall has an effect on the turrets that are built on them. Turrets on yellow walls gain more money per kill, turrets on brown walls deal more damage, and turrets on grey walls have longer range. Your walls and turrets can be upgraded when you have enough money.