As I imagine was the route for many others, I had gotten into the explore/craft/survive genre with Minecraft. That was a pretty revolutionary game for me, but as the years progressed and other games emerged, I grew bored of the genre. It felt like once you've played a few, you've played them all. Zombies, wolves, forests, islands, different veneers over the same structure. I was relatively done with the genre (The Long Dark is pretty damn good)
But it was Subnautica that rekindled my interest in that genre.
Subnautica's setting is easily its strongest element. There's a sense of wonder and mystery and beauty here that forest, cities, and other terrestrial places can't capture. Awakening in an escape pod after your larger spaceship crashes, you climb out and are welcomed with only an expanse of blue in all directions. The only way to survive is to plunge downwards into the aquatic landscape, catching sealife for food and gathering debris and materials to craft new gear and upgrades. What a world awaits you: kelp forests swaying in the current, bio-luminescent growths along the walls of dark deep caves, swarms of weird fish twisting through the water, coral tunnels and reefs, and more. But this beautiful environment is not void of danger.
Bone sharks swim among the kelp, the aggressive leviathan waits near the smoking crash site, and other aggressive lifeforms thrive throughout Subnautica's biomes. Luckily, with the right materials, you'll be well equipped to descend deeper and brave unexplored areas. Air tanks allow to stay underwater for longer, fins let you swim faster, knives and high-tech equipment like the stasis gun provide more effective means of defense. Lights, beacons, dive reels, air pipelines; the array of equipment to be constructed is varied and grows with each update.
It's an engaging cycle; new equipment allows you to explore more of the world (a reward by itself), thus acquiring new and better material and having access to better gear to explore deeper. In my opinion, the fact that every piece of equipment has a direct tangible effect, from faster movement or more air, makes crafting and collecting material more tolerable than in similar games. Once you're constructing bases on the sea floor or building submersibles, Subnautica really opens up, as you establish footholds in deeper terrain.
While the game is in Early Access, the developers frequently release significant content updates, introducing new biomes, new tech, new species, and more means to survive. The game is already solid, and only gets bigger and better with each new addition.