you do a physical experiment like a scientist. The aim of the game is to get the electron from the start to the goal, by jumping electron orbits. To do this, just click the nuclei of the current atom. Only jump when you are close enough to the next electron otherwise you die. And remember, your jumping distance varies between levels and atoms. As levels progress, it becomes more and more difficult to get the electron. You can try again for many times. Try to master some rules and the distance between atoms. It will give you some inspirations in learning physics. The principle on atoms and electrons is an essential topic for many scientific researches. Ready? Have fun.