The teleport was the bane of my existence lol, it kept teleporting the player out of bounds, and my attempts at trying to fix it made it feel inconsistent when you teleport close to a wall. For that mushroom section, were you using the downward slash to pogo off them (intended solution I neglected to teach) or trying to time your jumps on them (this is a bug actually)? Also I don't recommend using the teleport on that section, I think it's easier without it.
Thanks for playing though!