Subnautica below 0 does everything subnautica the first does, mostly worse. starting with the positives, art style was great, some of the new areas looked great. However the map is 1/3 of the size and there are less creatures. The map goes a lot less deep then subnautica does, and the final areas are tight corridors that are hard to navigate with enemies in them.
The story doesn't make a whole lot of sense and contains some plot holes.
While i still recommend this game it isn't the top of my list.