Now you can make and edit levels from within the game. It's actually really fun. You can access this from the bottom of the VS mode level select screen.

Here's a little timelapse of Anita and I testing it out:
https://youtu.be/UZYwZpTAVFo

I noticed some Birdsketball videos on Youtube that were running really slowly.
This was because the game was trying to render every frame, so when the framerate dropped below 60 the game would go into slow motion.

I've changed the game to run with a variable time step, which should maintain a consistent speed across all computers.