Hidden Oxygen is a challenging puzzle game. Your goal is to figure out the correct arrangement of oxygen atoms. Figure out the correct arrangement of oxygen atoms. Oxygen atoms cannot be adjacent to each other, even diagonally. Numbers next to rows and columns tell how many oxygens should be in them. Each carbon atom needs 2 adjacent oxygens If you got stuck? Press the hint button, which will explain how to come up with the next move. Enjoy playing Hidden Oxygen game here at Y8.com!