Demon!

DEMON! is a game of tag played on a screen full of PETSCII obstacles. Every time the player (a circle) catches the "demon" (a different circle), a new opponent will spawn. The game flows quickly, and the demons are hard to catch. The keyboard buffer is the true enemy in this game�your buffered movements will cause you to overshoot your quarry if you aren't careful.

In addition to the keyboard controls, you can use a joystick to play this game. I don't think PET joysticks were common, but they were an option.