Beautiful work.
FYI there's a bug if you accidentally try to pick up a piece on a tower with no pieces - it throws a multi-line error message. I've screenshotted it and added it below.
Suggestion: If you have multiple rows of towers, let the up/down arrow keys move from the top and bottom rows.
Ah, nice. This change already feels better. There seems to be some weirdness with the new up/down controls, though - sometimes when you try to select a tower that you just moved vertically to, the finger doesn't point to the top tile and it doesn't select. Moving left then right clears this, allowing you to select the tower again.
