Subnautica: Below Zero

The expansion pack is an upcoming paid DLC for Subnautica. The full release date is currently planned for early 2019. Currently all that is known is that the Arctic Biome will be a large part of the game, possibly the entire map. It is also known that a weather system will be featured.

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.

Currently known story details include the protagonist being a member of a research team sent to investigate Planet 4546B, using an orbiting research outpost called The Vesper. The Vesper's reasons for being sent are as follows;
 * Recovery of Aurora wreckage
 * Biomedical research
 * Ecological preservation
 * Resource exploration
 * [CLASSIFIED] (most likely investigation of Precursor technology)

Confirmed Features
Features that have been confirmed through various means.
 * Arctic Biome
 * New protagonist
 * Weather System
 * New Fauna, Flora, and Biomes
 * Penguin-like creature
 * Research installation

Potential Features
Features that the developers are still experimenting with that may not be in the final build.
 * Rock Puncher
 * Hovercraft vehicle
 * Arctic Reefback
 * "Pinnicarid" (Anomalocaris-like creature)
 * Glowing whale-like creature