Use the arrow keys to move the hero. You score is based on how long you can keep the hero alive. Monsters will chase after him, so you had better be quick.
You could run away at a constant rate but you haven't been looking after yourself, so you get fatigued rather quickly. Whereas the baddie doesn't get fatigued as quickly. It becomes this delicate balancing act of running just far enough away that you can pause to rest a little before running some more. As the Baddie's hunger increases, so does its speed; right up until it's fatigue outweighs it's hunger and it has to slow down to have a bit of a rest
Using Pause/Break will pause/resume the game.