At 2PM EST we'll be building levels live for one hour at http://www.youtube.com/flippflygames/live
Afterwards we'll be giving some stuff away and answering questions about the level builder (or whatever) in community chat. We'll even give away a few keys.
Check out the event page here for more details:
http://steamcommunity.com/games/racethesun/events/1423439783499592012
And if you're interested in building levels of your own take a look at our guide to Simplex World Creator:
http://steamcommunity.com/sharedfiles/filedetails/?id=227595974