I wish my recommendation here could be stronger, as the potential behind this game is massive, but it's failing to live up to it at the moment in very many ways. But ultimately, the number of high-quality puzzles in the game is so large that for anyone who really likes solving logic puzzles, it's practically a must-have.
As a massively multiplayer game, this world *could* become a hub of the puzzle solving and creating community and have a guaranteed solid player base, if it just had any way for players to communicate meaningfully, and maybe some excuses for them to do so. But there are no multiplayer puzzles of any kind, not really any in-game way for players to work together on anything, no way to make and share puzzles with other players, and most baffling of all, no chat.
To not have any way for players to talk to one another in-game is the most insanely self-undermining decision I've ever seen a game billing itself as an MMO make. I can only imagine what an infuriating meeting with the publisher that must have been for the developers.
It's frustrating as a player to be surrounded by people with likely similar interests (we all love puzzles!) who would probably be really cool to meet, but have no way to communicate, and have the multiplayer aspect of the game reduced to something that might as well have been supplanted by bots flying around in an offline game. (Nevermind that if it were an offline game, I wouldn't have to put up with lag and server disconnections.)
But while I agree with some other negative reviews that the game is sadly not quite living up to its promise there, I strongly disagree with some recent reviews complaining about puzzle quality when it comes to the grid puzzles. The grid puzzles are generally fantastic examples of construction. I've seen some complaints about the need to bifurcate in harder puzzles, but while bifurcation is a powerful strategy that will always work, and often the best if you're speed solving, that's generally *not* how they're meant to be done.
For example, the last puzzle I solved, still fresh in my memory, was a 3 star (i.e. 8/10 difficulty) puzzle which had a 7x7 grid with viewpoint numbers (i.e. "cave" clues that tell you how many cells are visible in cardinal directions from that spot inside the region of the same colour containing that cell), and where all white cells needed to be connected. At first, I was tempted to bifurcate, because almost no deductions seemed immediately available. But then I realized that in each corner, there was a viewpoint number with a 5 in it, and that fact forced there to be a single black cell along each edge of the puzzle, and more importantly, made the outer border of the puzzle rotationally symmetric. This symmetry meant that putting a black cell along the border would place 3 others, and often cut the white groups off, and that was the key to solving everything. The puzzle was still a good bit of work, but entirely doable picturing things in my head from that point.
Very often the hard puzzles in the game are hiding some deeper insight like that, and while the puzzle might be doable without it using bifurcation, is likely much less enjoyable that way. In general, it seems the people who made these puzzles *really* know how to make puzzles, and if it ever seems like something isn't doable without tedious trial and error, just leaving and coming back to it later with a fresh perspective might be preferable.
My positive review is mainly due to the grid puzzles, but there's enough grid puzzles that you can keep doing grid puzzles for hours every day and not run out for a long time, and even the easy ones are often quite satisfying and have something to communicate. Even if you don't end up liking anything else, you can definitely get your money's worth just on that aspect of the game alone.
There are also some extremely good puzzles of the sliding-blocks variety, and the majority of the match 3 puzzles are decent (somewhat surprisingly). Some puzzles of those types, especially a lot of the simpler sliding-block puzzles I would say are "filler" and a bit disappointing in that they fail to really communicate a coherent idea and many would probably solve themselves if you could shake the box randomly for a bit. The more complex ones are typically quite good however.
Beyond that, there's a lot of filler "puzzles" you find as you wander the environment, and I sort of wish that all of these had been given at least a little bit of the kind of care that the grid puzzles, match threes, and the better sliding block puzzles had been given.
While it's kind of fun to see if you can snipe armillary rings while flying, the randomly generated armillary rings puzzles are for the most part not very interesting. There is an enclave (dungeon) with what are obviously handcrafted armillary rings puzzles, and those were really good and required a bit of thinking about the structure of the rings and where you could position yourself in the environment. Everywhere else in the game though, they're kind of bland and mostly unsatisfying. It's rare for a randomly generated one to require any real thought.
Similarly for the skydrops. Once you've done 3 or 4 skydrops, you've experienced 99.9% of all skydrops, and only very rarely will you see something that was not a randomly generated bunch of locations that from one perspective makes a circle. (Every once in a blue moon, you'll see a triangle or trefoil knot.) Essentially all of them end up having an obvious location to stand, because some of the drops will generally end up clustered together near the ground, which is usually easily spotted from a distance.
The "light motifs", anamorphic graffiti that is plastered randomly around the environment and the goal is to find the place where it lines up, is similar in that it would be much better if they were a good bit more subtle and with more variation to the designs. Putting some thought into the placement, making some more patterns for them and choosing them carefully to suit the situation could result in something much more fun to discover.
Matchboxes (red and green boxes with symbols that need to be matched) are similarly all over the place, and while some of them are indeed in fun or interesting locations, most of them are a bit garbage and often feel randomly generated even if I'm not sure they even are. If every time I saw one of these, I could be assured that looking for its partner would produce at least a bit of satisfaction on finding it, I might not just ignore them 99% of the time.
But yeah, this game isn't really about any of that. It's about the grid puzzles, and those are amazing. If you like puzzles, despite all the caveats, and despite the fact that its future appears to be in some peril, I'd say it's *still* totally worth the entry fee. There are literally thousands of non-filler, high quality grid puzzles and most of them have an actual point to make about interesting interactions of the many possible rule variations.
As a last point, I'm playing on Linux using Proton, and there's a memory leak that causes the game to crash maybe 50% of the time if I tab out and back in (and the probability goes up dramatically each time I do it). The performance is also very poor despite my hardware being overkill. A native Linux build (even just an unsupported beta, if it could be made to run at all) would be very much appreciated.