While I was playing this I thought about how could challenge be added to it. Seems like the simplest ways (in theory, maybe not implementation) would be add a timer or multiplayer, and imply that players are racing, would probably be at home in a Mario Party.
Even then, with the multiplayer, it doesn't need to be overtly competitive, players could work together with one of them following the instructions, while others search for faster paths. I don't know if the instructions now give the optimal path, but would be fun for a group to explore that together.
Anyway, neat game!