The Unknown Worlds website reveals plans for Subnautica, an open-world (open sea?), underwater exploration and construction game the Natural Selection 2 developers say may represent a new genre. They have a small team prototyping this right now, and they haven't reached the alpha stage yet, so the three trailers they offer for now are just concept art and mood music. In spite of announcing it now, they say: "We are not ready to announce it and try to ‘build buzz’ or ‘attract attention’ – But we are ready, and excited, to share our work with you." On the other hand, they also say: "Every week, we will be releasing new Subnautica concept art, screenshots, design proposals, technical details, plans and progress. You can find out all about these releases via Twitter, Facebook, Google+, Reddit, and more." They explain this is because they are looking to the community for feedback all along the way:

The creation of Subnautica will be extremely open. We hope everyone in the Unknown Worlds community, and new faces, will be interested in giving feedback, sharing ideas, and participating in development. You can talk to most of the development team on Twitter and on the Subnautica forums. We will be opening up early Subnautica ‘builds’ (versions of the game) to a wider and wider audience over the coming months, and you will be invited to play.