The players are Blue and Green, who own Blue Atoms and Green Atoms. There are also Red Protons which are neutral. The object of the game is to own the most Atoms of your color at the end.
 
Click the green 'start thinking' circle to automatically randomize the starting position of the Protons.
 
Each player can move a Proton in any direction any number of empty squares but it must end up adjacent to at least one Atom (of either color). After the Proton moves it fuses, changing both itself and all adjacent pieces (Atoms and Protons) to Atoms of your color. Atoms cannot move.
 
The game ends when there are no more Protons left. The player who then owns the most Atoms wins. Draws are impossible.
 
Unfortunately, Zillions does not play this game very well. Turning up the thinking time only helps a little.
 
There is also a Cold Fusion variant.