This is a technical explaination.
I built this game using TIC-80, which is a free fantasy console, built around Lua - and each "controller" has 8 buttons - Up, Down, Left, Right, A, B, X, and Y.
It just so happens that (A) maps to [Z] by default, and (B) to [X], and so on!
Oh, and I never noticed that problem on level 2. Wait, I did - my collision might be a bit too tight... (but... how do I make a hole like 2px bigger when my entire collision logic is built around each tile having exactly 8x8px collision?)
Edit: Fixed typo.