The Game
The game that came to mind for this exercise was Binary Puzzle.
Rules + Mechanism
In Binary Puzzle you have an 2n x 2n grid, and you have to make it so every row has n 0s and n 1s, every column has n 0s and n 1s, there are no more than 2 0s or 1s consecutively, and no rows/cols are the same. Some of the mechanics that make the game fun is the binary entry mechanism. You tap once to add a zero to a cell and twice to add a one to a cell. It makes it super satisfying to hit a flow state where every cell you fill in gives you more information about another cell and you can just tap your way into a completed board.
Aesthetics
I would say the core aesthetics that make this game fun are sense pleasure (when you complete a row, the numbers briefly turn to rainbow colors and do a full in-place rotation), challenge (you can pick your difficulty level for each round, and certain levels have additional challenge features such as not telling you if a completed row is correct), and competition (there is a point multiplier in place that counts down slowly as time passes and reduces dramatically for any wrong number placed on the board). There isn’t a leaderboard for this game, it is just you competing against your previous best score. I think they do a great job of using game mechanics to make this solo game so enticing.
