Agree that is a simple game, for a game jam I was looking to setup a single strong mechanic, easy to play.
The game needs a more tune difficulty and add some extra layers of complexity, while keeping it simple. Initially I had a penalty for wrong sorting, but it came to punishing, considering people will try it for a few minutes and move to the next game, I wanted to keep a feel of archivement instead of dread. If I make this as a standalone mobile game, then I can think of other ways to make it more punishing and rewarding.