Subnautica: Below Zero

The Expansion Pack is an upcoming feature for Subnautica. The release date is currently unknown. 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.

Based on a tweet from game director Charlie Cleveland, it is likely that the Arctic expansion will be a separate game mode as he has stated that the protagonist will be a currently unnamed female rather than Ryley Robinson.

Confirmed Features
Features that have been confirmed through various means
 * Arctic Biome
 * Female Protagonist
 * Weather System

Potential Features
Features that the developers are still experimenting with that may not be in the final build
 * Rock Puncher
 * Glowing whale-like creature
 * Penguin-like creature