Sunless Sea is a trade and exploration game set in an underground ocean environment chiefly inspired by the works of H.P. Lovecraft, with a dash of Neil Gaiman and perhaps a touch of Hinchcliffe-era Doctor Who? Not sure about that last one. In any case, it's dark, funny, macabre, sometimes touching and never less than atmospheric. It's also, depending on your taste, slow, frustrating, and a bit light on content. But I'll get into that later.
The good first. Sunless Sea is primarily an exercise in atmosphere and imagination, and on those terms it's very well built. The game encourages you to avoid straight combat and stay illuminated or close to land at all times, forcing you to weigh consuming more fuel with a roundabout route against trips into dark waters that will slowly drive you and your crew insane. The result is a well-defined sailing environment which is easy to comprehend but never friendly. The imagination is lovely, too: settlements built into the carcasses of leviathans, an island of alcholic monks, an economy which thrives on storytelling and rumor. You get to hunt terrifying sea monsters, learn forbidden secrets, conduct espionage between Londoners and underground Mongols...
It's great stuff, and what's best about it is that it duplicates the Lovecraftian trick of making the universe utterly indifferent to you. You're not the Chosen One, you're not the revealer of all things or the savior of worlds. You're just a captain with a boat and a dream, and fate - or whatever force governs it - could crush you like a bug without noticing.
All of this is sweet and awesome and correct and I'll be playing this game for a long while. But there are, inevitably with a game this complex, some issues.
The first hurdle is speed. You can never sail at anything faster than what feels like a snail's pace. The reason for this probably has something to do with preventing the player from discovering too much of the game world too quickly, but while it's undoubtedly a relaxing experience there's just large segments of playtime when I'm not really engaging with the game. The process of uncovering the map early in a playthrough compensates for this, but once you're no longer a beginner it really starts to grate.
The sailing speeds feel like they hit just the right spot of too uninvolving to be rewarding and yet too involving to let you, for instance, pop into the kitchen and get a snack. This is why fast-travel systems were invented, people. Still, a fast-travel system would hardly be fair in a game so heavily dependent on immersing yourself in the actual business of sailing. I might recommend something like a waypoint system, letting you predetermine a path that you can set your ship to automatically follow - but that risks cutting the player out completely rather than simply weakening engagement, so what do I know.
I'm not entirely certain I like the text interface, either. Once you're used to it it's not that hard to navigate, but a beginning player especially is going to look at their journal and see a whole bunch of icons with meanings utterly mysterious to them. Discovering gameplay as you go is all well and good but for a long time I was essentially making decisions at random, which felt more frustrating than rewarding.
The book item that explains things is all well and good, except I'm not sure it's wise to put a beginning player through the process of pausing, finding their way to their inventory, picking out the book, finding the particular passage, et cetera et cetera. For use as a reference or a reminder on certain topics, yes, but I feel like I shouldn't have to basically stop playing to find out how to play for the first time.
The game economy is lovely and intricate, though occasionally it feels like there are gaps. That basically anything can be traded in the right venue - even "experience points", news, stories and memories - is pretty friggin' sweet. As a player you aren't just a sailor scrounging for bigger numbers of things - you're a witty raconteur, a spymaster, and a scholar of terrifying secrets. The trade really is the story. That's kind of brilliant.
Making the trade system work for you, on the other hand, is kind of difficult. Of course there's an intentional element of trial and error to be had here, but I do get the distinct feeling that there isn't enough variation in demand for different commodities to allow a player to figure out more than three trade routes (and at least two of those take advantage of the fact that parts of the map don't change in subsequent playthroughs). There are a couple of conspicuous dead ends where content was cut (e.g. the Antiquarian thing, which apparently doesn't go anywhere), which makes me think the developers are still getting a handle on the dizzying complexity of the economy and environment they built. No bad thing in a fairly ambitious indie project, but you can see the seams on occasion.
I suspect the game's main flaw is that its world is just a bit too small. Reshuffling parts works with a roguelike structure, but the fact that you can quit the game and keep going where you left off means that there are going to be playthroughs which succeed for hours upon hours - perhaps indefinitely - and content and sailing will inevitably start to get repetitive and - dare I say it - grindy. A bigger world would allow for faster sailing that wasn't overpowered, as well as more room for interesting strategy in setting up trade routes.
Overall, though, this is still a remarkably fun and intriguing game - if I wrote more about the negatives than the positives, it's simply because it's so damn hard to speak for gameplay that speaks for itself, and so much easier to spot flaws than triumphs (otherwise we'd all be master artisans, wouldn't we?). Point is, I'm looking forward to discovering more of Sunless Sea and what the developers plan on doing with it.