Thank you so much for the detailed feedback, very much appreciated! And I'm glad you seemed to generally like the game and the level design.
To start at the end, yeah, I've encountered that bug a few times, but I only have a vague idea what might be causing it and since it's so inconsitent to reproduce, I'm not sure how quickly I'll find a fix for it.
Yeah, the complexity of the game leading to a lot of open ended puzzles is definitely a challenge we haven't completely figured out how to handle yet. We have a few thoughts for possible improvements by either restricting the player's ability to rotate the cube (e. g. "control panels" that the bunny must stand in front of in order to be able to switch to rotation mode) or encouraging the player more to find the elegant solution (e. g. by giving a PAR score of rotations for each level). We might have to play with those options a bit and figure out what works best.
"Cliff Diving" was originally supposed to come earlier excactly to teach that mechanic, but during testing, it seemed a bit too difficult for that early spot. In general, I think W2 probably needs the most work right now.
Adding a pattern to the walls / background is something we briefly considered, but somehow I just didn't get around to implement it and it fell off our to do list. Thanks for the reminder!