Subnautica: Below Zero

The expansion pack is an upcoming paid DLC for Subnautica. The full release date is currently planned for mid 2019. Currently all that is known is that the Arctic will be a large part of the game.

The Arctic expansion will be a separate game mode with a different protagonist rather than Ryley Robinson, and takes place in a separate map. It will also be set in a time period after Ryley Robinson has escaped Planet 4546B.

Confirmed Features
Features that have been confirmed through various means.
 * Arctic
 * New protagonist
 * New Fauna, Flora, and Biomes
 * Penguin-like creature
 * The Vesper
 * “Glow Whale”
 * New, not yet known vehicle
 * Twisty Bridges

Potential Features
Features that the developers are still experimenting with that may not be in the final build.
 * "Squid Shark” creature
 * Rock Puncher
 * Arctic Reefback Leviathan
 * "Pinnicarid" (Anomalocaris-like creature)
 * Weather System