This is legitimately a really fun game! Really shows how it doesn't take complex concepts to make great core mechanic. There's so much meta-strategy that can be derived from such basic controls, so my hat off to you. No idea how the top leaderboard scorers have so many points though... I suspect shenanigans.
My only issue what that is wasn't clear at first that color of the *cursor* had to match the color of the box to score points. I instinctively thought it was based on the color of the electron, which is what is actually being pushed into the box, but it stays red the whole time. Kinda confusing.