go to the menu and hold left before pressing 's' to do the speedrun. Your timer won't start until you press another button

Also, holding down and continuing to hold down will wait until it is possible to get in a crate, then it will enter on the first frame. This will be useful. To get out of the crate while holding down, use the trick where you hold down for a bit and release and it will automatically jump.

Hmm, the "hold left before starting the speedrun" thingy can cut a whole ~1 second from the run.

I will allow it, since the time is based only on the in-game timer. I updated the rules with this change.

EDIT - now that I look about it more deeply, it won't cut any significant time in the first level, because you need to jump anyway to get inside the crate, and you can jump right from the beginning position.