A little skip in Level 11 I know of, but is really hard (at least to me).

Basically, at the very start, you don't have to wait for the second spear to get out of the way. If you land right at the edge of the platform, you won't get touched by it's hitbox, and you can go and jump away, which I think will shave maybe a second, but this might also affect the platform cycle, which will allow you to catch it faster, so it will probably actually end up saving about 4 seconds in level 11.

This isn't really a guide, and I don't know what is allowed as one, but I thought I'd just put this up here.

BasmatiCentauri

Blue Yibba Dungeon Escape 

Level 8

Level 9

Level 10

Level 11

Skull Sign

Akuretaki

keyboard input

touch screen input

input device

edris