Don't let Blender's free, open source availability put you off. This is an incredibly powerful, versatile, and polished software package. There are areas where Blender isn't the correct tool, although they're few and far between, but even in those scenarios it'll get the job done. Can't recommend it enough.

I haven't tried crack, but I'm guessing it feels similar to this game.

I thoroughly recommend this game! I'm not usually a big fan of single-player games, but this is one of the best games I've played, hands down.

The atmosphere is one of the most immersive of any game. The sound design pulls you into the world, whether it's the low rumbling of the reefbacks, or the terrifying cry of the leviathan, even the sound of climbing out of your submarine in your moon pool, everything evokes an emotive response.

Subnautica evokes terror like nothing I've seen before.

I'm very impressed with the performance on my dated system. I just squeeze through the minimum system requirements, but am able to play at close to 60fps on medium graphics.
I experienced one crash during three hours of play time, but was back in the game in no time.
In terms of game play, while you can stick to a Warband style play through, other options are a lot more viable in the early game, such as trading or starting your own enterprise.
At this stage the quests feel fairly generic, but I expect that to change with development.

Overall, a very complete and stable experience for early access.

Finally, a game with everything. Whether you're a twitch shooter or a space sim junky, if you like commanding huge armies or being the leader of a small elite team, maybe you're the next kareoke sensation or the dance master, this is not the game for you!

If, however, you're looking for something to put on your second monitor while you work, something that requires no input but tricks your subconscious into thinking you're procrastinating, (that may seem quite specific) this is the game for you!

My goal is to have more hours in this game than in CSGO! Wish me luck, brothers (there are no girls on the internet)

My hours say it all. Although this game may not the prettiest for 2015, the gameplay more than makes up for it. In terms of a full singeplayer experience, look no further. That said, I would recommend adding to the experience with the floris mod.