Raresloth's King Rabbit [Free] is a lovely game and has been expanding ever since its release. In March, we got the Emerald expansion, which added 64 levels to the game, and now the developers are working on Ruby, another 64-level expansion. However, this one is going to be created by the players rather than the developers. Raresloth is running a design competition—since the game now features a level designer—and will pick the best 64 levels created by players to be featured in the Ruby expansion. All you have to do is create a level, publish it, and share your level on Raresloth's Twitter account. The competition will run until May 15th, and the update will hit the App Store June 1st.

If your level gets selected for the expansion, you'll get the $1.99 expansion for free, get 1200 in-game diamonds (worth $11.99), and your username will be shown at the start of the level. Pretty cool. If you're just started designing levels or simply want some guidelines, check out Raresloth's level design tips.