The principle of this game is fairly easy: you start off as a small sphere shaped object (I call it the “cell”) and seek to be the largest object on the rectangular shaped map. The rules are simple: if you touch a cell smaller than you in dimensions, you consume the counterpart and grow larger. If you make contact with a larger object, you will be consumed. You can move only by discharging mass from within your cell in the opposite direction you wish to move along. The repulsive force will accelerate your movement. Of course this will make you shrink and be exposed to new threats. So you better not waste too much mass. You are given only one tool and that is the control over the pace of time.
While the rules are readily comprehensible, the gameplay might be a challenge. There are modes where you are concerned with finding the most economic “route” of consumption from a logistical point of view. In another game mode you will find AI controlled opponents who try to grow large as well and eat you before you can eat them. Lastly, you will find a game mode where the organisms are organized like stellar systems – these maps ultimately require basic knowledge of orbital mechanics in order to be mastered.
No matter what game mode you choose, basic knowledge about mass, force, acceleration, velocity, momentum and gravity will come in handy. I wouldn’t say that this is strictly a physicist’s game though. I am sure the game is also fun for people who play it by intuition only, I would recommend it to any puzzle solving gamer. There are an infinite number of maps - each time you beat a map a harder one will be generated, what a perfect challenge!