Sea of Thieves is going to be supporting an even bigger player base than it initially could have, according to a new announcement at Gamescom. The game will officially be supporting cross-play on launch, meaning players on Windows 10 and Xbox One will be able to interact with one-another seamlessly. While this isn't surprising news, it makes things simpler for people who have been anticipating the game with friends who don't have the same hardware.
— IGN (@IGN) August 20, 2017
Sea of Thieves is in Alpha right now, and there are a few people who are currently testing it out - we can expect it to have a full release at some point in 2018, but we have nothing more specific in that. The game intends to mix together Guns of Icarus-esque ship gameplay, in a cartoony, whimsical pirate atmosphere.