Whow, that is a lot of feedback! I very much appreciate that you wnet deep into analyzing the whole game. Thank you!
About the controls: Even when developing the game I sometimes encountered that the player would suddenly clip into the wall when phasing through platforms or when teleporting, but at the end I decided to not really look too much into it, since it would take a lot of time to get the controller and collision working flawlessly. Though I do think that I have messed up when programming the controller, so maybe that had something to do with it. And everything can't be perfect in a 3 day GameJam ;)
I very much agree with you on the art. Because I'm not great at drawing I resorted to what I was able to do, and that was the result. As I was putting in the drawings into the game, the varying sizes and outlines of the different drawings were also kind of weird.
Either way, I am very glad you enjoyed playing it and gave all of this feedback! Thanks to you and people like you I can apply those feedbacks in later projects/GameJams. Thank you very, VERY much!