Being able to draw in perspective is a huge improvement. Thanks to that option I spent much less time trying to connect lines from different cube sides, than in previous version of the game. I just kept toggling it on, and I wish there was an option to keep it on by default, because every stage I started with enabling it.
There was one time when I kinda finished the stage, but the ball did not go to the exit, and after replaying, the cube had no collision on that side (I was not able to draw on it, and the ball was going through it). Not the worst thing that could happen. I just needed to exit to the main menu, and re-enter the stage. That's when I realized you don't actually show stage names when you go from stage to stage, which made is hard to find which stage I was on.
The mechanic with rotating the whole cube felt much better, than just rotating single wall. Still kinda hard to wrap your head around, but I enjoy the challenge. What makes it unnecessary difficult is on some axis the cube doesn't rotate (as in the camera doesn't move) the way you would expect. I think one way you could improve it is if you had some ui buttons in corner for navigation.