The real Alpha 6 "April Test Build" will be releasing on April 29th. And a few days before then, on April 27th, the official JohnsterSpaceGames discord server will be going live! Some of the new additions you'll get to see in this version will be the launcher (shown here), a partially finished multiplayer gamemode, and a screenshot gallery room in the Funseum (aka the museum of fun) where you can view some screenshots you have taken while playing! To take screenshots, just press F2 (or the camera button if you're playing the mobile version). As for viewing them, you just have to hold down F3 for a few seconds to open the screenshots folder.
