Its not a sequel then, as its not related to Terraria at all.
Anyway, it looks good and here is a link to find more info and a place to purchase it. http://store.steampowered.com/app/211820/
Current prices : $14.99 USD for a single steam copy
$44.99 USD for a 4 pack of the game.
Copy paste of the blurb
In Starbound, you take on the role of a character who’s just fled from their home planet, only to crash-land on another. From there you’ll embark on a quest to survive, discover, explore and fight your way across an infinite universe.
You’ll encounter procedurally generated creatures and weapons, discover populated villages and abandoned temples. Explore planets dotted with dungeons, eyeball trees and treasure. Make use of over a hundred materials and over one thousand in-game objects to build a sprawling modern metropolis or a sleepy secluded cabin in the woods, and do all of it alone or with friends!
Starbound lets you live out your own story of space exploration, discovery and adventure. Settle down and farm the land, hop from planet to planet claiming resources, or make regular visits to populated settlements, taking on jobs and earning a living. NPCs are scattered about the worlds, offering quests and challenges for those looking for a little extra excitement in their lives.