This update pertains to the secret game mode (have you found it?  If you beat the game, it will tell you how to activate it).

Gamemaker seems to be lacking when it comes to reading controllers.  To fix an issue where multiple connected controllers caused interference when reading the right analog stick, I made it so that you have to tell the game which controller port to use (only in the secret mode - during the regular game, it will still read inputs from all controllers).

To change controller ports (there are 12 available in total), press 0-9 or PgUp or PgDn.  If you want to see which controller port is currently being accessed, you can enter debug mode by pressing "V" during a puzzle.

Again, this is only relevant to the secret mode.  The rest of the game is unaffected.