I like it but wish the puzzle had gravity at the x,y intersection and not just the x axis. For example if you clear out a row it would shift the other rows over to the left.
I think whether to do that is a design choice, though. The current setup puts a penalty on clearing center columns early, effectively splitting the game in two.
What a great mnemonic, I’ll start using it even though I typically don’t mix the two up! Thanks a lot.