I wanted to wait to play enough of this game to properly form an opinion before I wrote a review for it. I now have at least 30 hours, and finished all story content available in EA so far.

The bottom line:
If you enjoyed Subnautica and or BZ, you WILL enjoy this game. It follows the same basic format: multiple biomes of diverse, beautiful alien aquatic life, snippets of story amongst the wreckages of *redacted*, focal story points as you brave deeper locations, and big big scary boys. With explorations and base building, you can get a lot out of the game, even in this early form. If you beeline the story, you're probably looking at 8-10 hours of gameplay.

Performance Issues:
This game is EA, so don't expect a 100% polished masterpiece. That being said I barely had any issues. It runs on a satisfactory 55 fps on Epic on my high-tier but older PC, and I really only experienced some lighting bugs, nothing game breaking.

Criticisms:
I will say, the sound design is a touch disappointing as someone who loves the OSTs from 1 and BZ, and genuinely listens to them regularly. A lot of the music is so familiar that it sounds like a remix of a BZ song. That being said, some of these songs may be placeholders, so this criticism should be taken with a grain of salt. My hope is that the game carves its own unique identity with the music, just as BZ did.

Strengths:
The game is GORGEOUS. The lighting is probably 50% the reason behind my high playtime; I've spent a lot of time getting the perfect angles of the rays of light breaking through the landscape for screenshots. The creature designs feel distinct from 1 and BZ, I don't feel like I'm on the same planet. I enjoy a new system they added for progression-locking new areas; I won't spoil it though. It makes the gameplay loop feel different enough from Sub 1 and BZ, where really the only barriers to exploration are depth modules and bravery.

All in all, is this game worth it? YES, but that is what EA is for. Are there some areas that could be improved, yes, is it as strong as a game as the first, maybe no, but it's still a great time. I should also mention I've been playing 100% solo, so I cannot comment on the MP experience, but that seems like it would add a really fun element to the game.