OK, explanation to my 3: Empyrion: Overall game mechanics. Also devs and community interactions, the improvement of the game. Galactic: Large sandbox space travel exploration with several modes of how to start and continue playing, SP/Coop & PvPvE. Survival: Try to stay alive fighting the elements and whatever attacks, preferable not die even if no real death penalty yet (but can make your own "rules"). While collecting resources to craft needed stuff. Along building your own vessels and bases, or use others from the Workshop system.