Devil's Tower

Devil's Tower is a single screen shoot 'em up viewed from the side. The screen is split in two by a large mountain with the player being located on its left side and waves of alien attackers appearing on the right side. The aim of the game is simply to kill the aliens by sending projectiles over the mountain while at the same time avoiding their projectiles. The player can move left and right and shoot projectiles from four different angles. Additionally there is an option to drill into the mountain which then offers some protection. There are three kinds of enemies: attackers that launch projectiles from the ground, protectors which fly past and build force fields above the ground units and robot climbers which climb the mountain and attack from there. As the game goes on, the space available for movement shrinks which makes it harder to avoid enemy projectiles.