From the Steam store page:
GRAV is a sand box experience where you explore a multitude of planets, hunt strange alien creatures, build and defend outposts, craft weapons and armor, and attempt to survive against other players in a hostile environment.

We here at BitMonster has been working on GRAV for about 5 months and feel that getting the community involved earlier is vital to a great game. We plan to launch GRAV as Early Access and work closely with the community on how we evolve and move GRAV forward!