Thanks for the kind words Paal! Great feedback, regarding which, we've added F5 to restart the current level, but you can also press Z to undo any number of moves. This game was made for a game jam, at which we were to showcase it, so the F10 key was left in intentionally so we could skip to the ending without going through all the levels when we presented it. We're planning to do another polish pass on it soon, we've already begun.