Destroyed the CS time here, which was 1:17 (!). The key move here is the enemy throw up to the blue key, which is supposed to require puffy Wario from the bottom level. Can still come down a second or two!
Didn't take long to learn this at all. CS time here is 1:08, that's probably pretty optimal. Key improvement: in red key room jump off the ladder at the top in such a way that the screen doesn't scroll.