Subnautica is a very good game. What starts as an ordinary survival game (with a twist of being almost completely underwater) slowly unravels a deeper lore and immersive story that has you exploring alien history and piecing together the events that led to your ship being shot from the sky so that you can figure out a way to escape.
Although the graphics are somewhat lacking sometimes the scenery still manages to be incredibly beautiful, terrifying or both.
The game creates a very realistic atmosphere that has you on the edge of your seat gripping your mouse or controller in fear at what could be lurking in the shadowy depths, made even more blood chilling by the occasional distant sound of a hungry predator and the subtle background music. It’s tense.
The only real issue with this game is the long (2-3 minutes) loading time and terrain generation issues that can lead to you getting stuck below the map or losing your seamoth. These issues are not enough for me to rate the game any less highly though.
Definitely play it if you haven’t already, especially if you’re planning on getting the sequel, subnautica: below zero