My mobile game of choice to pass time and relax is definitely ball sort. This simple game exists in various implementations, but at its core, it involves taking a disordered system and, following a set of rules, restoring order. As far as mechanics, the version I play has an algorithm that takes 9-13 tubes of four similarly colored balls each and permutes them, with two empty tubes. Only the top ball in each tube can be moved, and a move is only valid if the receiving tube has space and either no balls or a matching-colored top ball. Due to the small number of tubes, most games go by without having to think much about strategy, but it stays just fresh enough because each puzzle is different. Every fifth puzzle or so, I’ll have to stop and think harder about a puzzle, planning many moves ahead and intelligently choosing which balls I move when to solve it. The relief and satisfaction felt in the final moves one a tough puzzle has been resolved is quite cathartic. Of the core aesthetics defined in the Hunicke et al. paper, this game certainly falls into submission, and it fills its role perfectly for me.
