The player controls a small black atom with red spikes called a Chemic, which can adhere itself to passing Moleks, which come in four different colours: cyan, green, pink and yellow. It must use these to duplicate the shape shown in the middle of the screen. When you successfully do this, you will get bonus points. There is also a malevolent clump of balls called the Atomic that floats around the screen, and will destroy your helpless Chemic if it merely touches it. If a Molek goes into the wrong place, press the reject button to throw it back. Every four stages there is a challenging stage where your Chemic can shoot Moleks in four directions at the Atomic. From World 2 onwards, there are Power Moleks that will let your Chemic attack the Atomic for a short period of time. They don't last for that long, though.