Thank you for playing. I'm glad you liked the game :)
I'm really proud of the shifting mechanics, even though I wish I would have explained them better to the player. The code behind it is pretty messy. It's a bunch of if statements checking the last turn of the player and its orientation to decide what tiles should appear or disappear. I made a smooth transition using a mask to hide the tiles when they are behind the player.
You got pretty far into the game. Many people couldn't pass the first 4 levels. Well done!