tl;dr - big sale or no-go experience, heavily padded gameplay, mods feel mandatory. mediocre at best.
It's not particularly bad, but it's also not particularly good.
I originally played this when it was brand new to Steam and was still very obviously a beta-quality product with large chunks of gameplay very obviously missing. Enjoyable to an extent, just not a product worth putting money into or even giving an extended playthrough to.
Fast forward to now and they're supposedly working on a sequel and gave this game away for free, so I picked it up again, and apparently almost nothing fundamental has changed. I was able to use existing game knowledge to "speed-run" the game doing exactly the same things I did previously and clear within an hour, with no major new objectives beyond a few new mandatory craftables in the middle. This isn't because I went out of my way to do so, but just because the game consists of such an unbelievable amount of padding that bypassing it by just remembering where things are rather than haphazardly crawling around in the still-awful movement of this game's attempt at zero-grav controls (space is one big icy surface apparently, who knew!) legitimately shaved that much time off. I imagine in a normal playthrough this would also take even longer because of having to run back to the ship so damn often for the sake of oxygen replenishment, which is just as awful as it was during that early beta despite it being probably the single most common complaint I saw at the time. This isn't to say it's incredibly short either, there's a decent chunk of stuff to do that wasn't there before, but it's all optional and doesn't seem especially appealing when the game does a good job of wearing me down to begin with. And is mostly, still, very padded content that involves a lot of feeling about in the dark for a few moments, going back to get more oxygen, then feeling around in the dark some more. They give you oxygen tank upgrades around the same point that you're going so far out, that the amount of time actually spent on exploring is about the same, you just have more travel time. Even tools are incredibly easy to craft but incredibly fragile, requiring constant trips back to remake them. I don't want to accuse the devs of trying to prevent refunds, but I also really have my doubts.
There's more story to it than there use to be. Kind of. There's an intro cutscene and an outro cutscene, and then the entire middle of the game is a bunch of crude humour, which might be funny at first but gets kinda grating when it's not only the only voiced content you're hearing but is so frequent that the game is quite literally interrupting dirty jokes for other dirty jokes. My nephew watched me play about 15 to 20 minutes of it and despite being in the target age audience for constant bouts of jokes about piss, crap and sex, even he'd wound up tuning out pretty fast. There's a few environmental set-piece jokes too, and the game absolutely rushes in to ruin them having any humour at all by giving a small one-liner that rarely contains a joke in and of itself so much as just existing to go "look! look! we're funny!" and ruin the joke that was there. The ones that *do* contain an attempt at humour still do such a good job at ruining the visual gags that any humour in them is ruined too, anyway.
It also still has the LITERAL-DAY-ONE bug where changing language doesn't affect the UI until you restart the game. Devs insist this is because the UI is textures that don't get actively reloaded but modded object textures can be changed with language without a reload if they're set up to do so, so that's a lie.
All this is to ultimately say the game is the same incomplete experience from 6 years ago, just now with a lot of polish to hide those incomplete edges. It feels like the type of game where modding is mandatory, and a default price-tag of £20 is more than a little outrageous. I've wound up with less interest in the sequel than I had going into it, and I wouldn't say anything less than 75% off is an acceptable pick-up for this game. Hell, I'd honestly argue that it holds too little value to care about even when it was available for free.
This game was originally released quite soon after Subnautica's "final release" and for a time appeared to be trying to ride it's coat-tails before *trying* to build it's own identity, and now that Subnautica 2 is in Early Access that's the time they pick to announce a sequel of their own? Honestly just get Subnautica instead. If you like it, pick up Subnautica 2's early access from there. It's the same core experience but with the option to build your own base, significantly more exploration room and meaningful progression. Below Zero can be skipped.
