Well that sucked 377 deaths and a half an hour of in-game playing time out of my life. Whee-ha!
What made Step Aside suck for me wasn't so much the enemy misalignment, but having to make it through the spike gauntlet
before even being able to get up there. It was infuriating getting down to the bottom, waiting for the enemies to get just right, and then flipping into spikes on the way up.

Infinite Possibilities and And Beyond were kind of flukey to me too. In Infinite Possibilities, what got me were the small blocks ending the gravity lines on the left and right edges. I'd land on one without realizing it, throwing off the bounce timing, and then I'd ram into an enemy with my face. And Beyond is great, except for how the two enemy pairs with the gap in the middle are right up against the gravity lines, so you can actually be killed from the
other side if you bounce while one is directly beneath/above you. It was hard enough making it past the enemies without also having to worry about landing wrong.
*All that said, I'm pretty sure the room I died the most in was none of those, but Feel the Rhythm. Just could not consistently time the very first gravity line crossing at all.
Definitely a lot of tightly-designed challenges here. Love love love Swing on the Spiral in particular.
*: Eventually I figured out a super neato path through And Beyond that negated all that. With the right timing, you can flip into the first track while holding left, fall through the gap into the second track and switch to holding right, and make it past everything without ever having to correct your course!