celestia.io is a free for all game where you eat to grow and strive to be the biggest of all.  Destroy other players and they explode to become food.  Destroy larger players and they become more food.  However, excessive greed may come with a penalty - you slow down while eating, making you vulnerable to attacks by other players competing for the same food.

    Movement is done with your mouse (or by touching the screen).  Fire by holding down your left mouse button, and boost by using your spacebar or right mouse button.  Your health can be seen from the amount of glow ar

    Move over food to eat and get bigger.  Fire at other players to inflict damage on them, and if you succeed in killing them, they will explode in a spectacular supernova.  Be wary of other players firing at you - you are food to them as much as they are food to you.  If you ever need a quick escape, you can use boost to move faster, but use boost sparingly - you eject mass when boosting.