This is probably one of my favorite games ever and it will stay that way for a loooong time.
Spoiler Alert is now in full effect!!!
Subnautica is survival type game, in which you are stuck on the oceanic planet known in the games universe as planet 4546B, and the only way you can go is down. After you crash land on said planet, you have to do anything to survive.
Story reveals slowly as you progress through the game. It`s not told by other characters as there is no one except you on the planet, and a lot of fishes. It`s told as you collect tablets or in-game known as PDA`s, hidden structures, radio message and many more.
Now let`s begin with gameplay elements. It`s typical survival game where the main point is to survive as much as possible. You need to collect materials around you and make different items from materials. As you explore your suroundings, you will find plans for more items to unlock during your playthrough, many tools to help you with exploring, different diving suits and upgrades,from 1 man vesels to submarines and even mech suit. I could list many more items but I don`t want to waste your time too much.
It just seems amazing to explore an under water world just like that even if its imagined, simply that experience is incredible, I can`t explain it well enough for you to understand, so if you have money and time to spend buy this game, as I said it will be amazing experience. But wait, don`t do it if you suffer from serios case of thalassophobia. Yes, this game can you some major creeps as well. When you are high on surface where ocean floor is about 100m deep, try not to look down... Never mind you will have to so you can go down but you don`t know what can jump out from that deep water. Well you can know if you are seasoned player like me. I finished game multiple times and still counting. But thalassophobia isn`t only way to get creeped out. Just exploring different biomes can bring you execitement or shivers.