The high/lo feels unintuitive to me .. Down on a P makes me thing R-Z not A-O. I actually think left/right is a more clear visual and mental model. I like the game and it is quite difficult sometimes to come up with a legal word that gives you an improved anchor point for the binary search.
The name of the game is a combination of High and Low. So high would mean right or after the letter and low would mean left or sooner in the alphabet. I’ve added a one time display of the rules before the first game.
Apologies, I meant that the UI shows the up and down arrows in the blocks in a way that is unintuitive to me.