Demon

Demon is a fixed-screen top-down vector graphics based shoot-em-up. You control an astronaut using five buttons. Two turn your character left and right. Another moves them forwards in the direction they are facing. There are also buttons for firing a laser shot, and to activate a panic bomb which will kill all enemies on screen.

There is only one screen, which contains two large rock formations that can be used as cover from enemy fire. Enemies enter from off-screen, and attempt to kill you. You can earn points for surviving, killing enemies, collecting fire gems and returning them to the cargo shuttle which perpetually crosses the screen from left to right. Picking up the gems will restore your laser power, which is drained every time you make a shot. The gems will explode if you take too long to get them to the shuttle. Returning ten gems to the shuttle will give you a bonus life.

Enemies are of three main types. The standard enemy is a drone, which moves a bit like a slug with a gun on its back. At the start of the game with the easiest difficulty, these move slowly and do not fire. The second enemy is a fire ball, which will spawn from a fire gem that is left too long without being collected. Finally, the demon appears only occasionally. It moves rapidly, may leap onto the rock formations, and blasts out bolts of electricity in all directions. As the game progresses, the difficulty increases until you eventually lose all of your lives.