Maybe the tower could be a ballista of sorts? Really long load time, good range and fires, penetrating through all enemies damaging them. Could even make it so it's more utility with a fire rate half of the cannon or so, and when it hits enemies, it knocks them back. (The really slow fire rate is to make the knock back not stop enemies from attacking by constant knock back every time they get close to the base). Idk, an idea

