Boundless has been kicking around for a while now, in various shapes and forms. Formerly known as Oort Online, studio Wonderstruck renamed it Boundless in 2015, at the same time as it was announced for PS4. Its been in Early Access since 2014, but now an official launch is slated for September 11.
As I've previously written, Boundless is a Voxel-based MMORPG which has fairly attracted a bunch of comparisons with Minecraft. But while it does boast building and endless, procedurally generated landscapes, it seems to be a much more focused affair, even while it allows the freedom to do virtually whatever you want.
"Starting with your first humble campfire, will you live a nomadic life in the wild, or found a new settlement with your allies from which to grow your empire?" reads the Steam description. "Rally citizens to expand your city, competing to become the capital of your world and claiming the title of Viceroy."
You'll also be using portals to move between connected worlds, and it appears that you'll need to work hard to protect your home from other players. It will support crossplay with PS4, and there will be no monthly fee. Not that anyone's really doing that in 2018, unless you're Blizzard.
Here's a new trailer: