I personally really enjoyed Subnautica. The serene feeling of diving around while listening to found tapes, doing everything at you own speed, while learning to live in the local ecosystem.

Especially diving into the deep zones really makes me relax. Absolute darkness, only the light from your cockpit and the sounds of the beings which you cannot see. Sometimes the sound of the hull of your sub scraping against the obscure walls of the caverns. Navigating only using the way points that you set after carefully having probed the way using the smaller craft, which could not actually go the full depth.

And then I got the sonar upgrade, which kinda destroyed the vibe, so I disabled it when going deep.