We have just launched the Closed Alpha stage of the Screeps Arena project! All Closed Alpha owners should be able to download the game and start playing immediately. There is a private discussion forum on Steam aimed especially at the game owners where you can participate. If you are an owner, start with reading this post:
https://steamcommunity.com/app/1137320/discussions/2/3132793555949735254/
If you are not, you can join our Closed Alpha by using Access Keys in the Screeps game. Welcome!