You control a constantly moving dot that can turn left or right. This dot leaves a toxic resin everywhere it goes, so crossing your previous path will be fatal.
The point of the game is to collect dumbbells, which appear randomly — the more dumbbells you get, the higher your score. When you get a dumbbell, it cleams up some of the toxic resin nearby, enabling you to pass through small gaps in your path. Each dumbbell counts for 1000 points, and your score also goes up a little as you move around.