Who was it that managed to beat this on the second try, with around ~30 seconds left? Anyway, this particular challenge seems to be very easy for some players, while being really hard for other. The main suggestions I can give are:
* Memorize carefully where the checkpoints are, and try to plan a fast way to go between them. ...search Hoffmann for a map over the checkpoints
* Remember that whenever you collide with a wall, if you hold Up Arrow, you'll get a vertical boost. This will enable you to navigate the level a whole lot faster.
* Whenever the fly power is on the way to the next checkpoint, use that!
If you get the full version and want to do the speedrun challenges last, you should avoid these stars:
Cham, Haakon, Goldschmidt
I never posted it on the forums, but I did it on my second try with 30 seconds left, I remember clearly. I was very proud. =]
Then counting flowers on the one planet kicked my ass because I didn't find a secret area...