Starmade is a 3D space sandbox shooter that's not unlike Minecraft. Featuring building and crafting with blocks, it also allows you to create spaceships with weapons, shields, thrusters and more.
With Single player and multiplayer you can play on your lonesome or with friends, and with the catalog system you can build ships that you can import onto the server you're playing on. With Factions, shops, and valuable loot to be had what's stopping you from playing it now.
It's currently in Alpha, and is Free-to-play.
You can find some of my builds available at http://benchminecraft.com/