I love your game! It seems that the concept "balance" is explored in the game mechanic, the art, and the narrative. Players are always switching between the left side and the right side, finding a balance to maximize their points.
Art-wise, it seems that you are trying to find a balance for the amount of light (and darkness). I love how this integrates so well with the game narrative!
Also, love how juicy your game is, especially the bounciness of the electron as well as its destructiveness - really satisfying.