I don't want to do an official review of Darkest Dungeon for two reasons. First, it's been a while since I played it, so my memories of it aren't sharp enough for me to trust them completely. Second, though somewhat related, I played it back before the release of the antiquarian class, let alone the Crimson Court DLC or various other changes, so whatever I might have to say about the game wouldn't be a fair reflection of its current state. However, I think it's still a game with a lot that's worth talking about, and since I've got too much else going on these days to replay it in the near future, I might as well talk about it now.
Darkest Dungeon is an odd game to describe, since it takes elements from various sources and bundles them into a fairly unique package. On the surface, its genre is a hybrid of RPG (form a party of up to 4 characters, whose abilities are determined by their class, level, quirks, skills, and equipment) and roguelike (random dungeon generation, constant autosaving, and permadeath). In execution, it places a lot of emphasis on resource management (particularly stress management) and grinding. Let's tackle these one at a time.
New characters are generated randomly at the stage coach, which brings in anywhere from 2 to 6 fresh meat sacks per visit to town, depending on how much it's been upgraded. These characters can be from any one of twelve classes: abomination, antiquarian, arbalest, bounty hunter, crusader, flagellant, grave robber, hellion, highwayman, houndmaster, jester, leper, man-at-arms, occultist, plague doctor, or vestal. Each level zero character starts with a random 4 of their 7 combat skills unlocked (aside from the abomination, who starts with everything unlocked but can only access 3 skills aside from transform in either human or beast mode), along with some camping skills from a pool of common and class-unique options. While the classes can be grouped into traditional RPG categories like front-liners (crusader, hellion, man-at-arms, etc.), back-liners (arbalest, occultist, vestal, etc.), and hybrids (highwayman, jester, etc.), most of them can be shuffled around and still function quite well in atypical positions if their combat skills are set up for it, except for lepers and maybe flagellants. It's a pretty ambitious setup, and there's enough depth to it that my opinions on the class tier list changed quite a bit over the course of playing the game.
There's something else that also makes each character special, though, and that's their quirks. These are an assortment of randomly-generated traits (which can be added to each time the character goes through a dungeon mission) that can range from useful (e.g. increases resistance to a status effect) to fairly inconsequential (e.g. refusing to use a certain service in town for stress relief) to really bad (e.g. increased stress gains from eldritch creatures). There's a sanitarium in town which can be used to either erase quirks that you don't want or to lock in up to 3 positive quirks, though the costs for either action are substantial enough that you can't keep a clean slate on everyone. It's a pretty cool way of helping to differentiate between characters, and you can have some fun with things like setting up a dedicated beast-killing party or making a point of locking in quirks that increase the chances for critical hits as a means of helping relieve stress indirectly. I really liked the quirk mechanic in general, even if there were a few that were absolutely wretched (e.g. unless it's been toned down in recent patches, kleptomania basically makes a character unusable, in my opinion).
The game is split into five areas: the ruins (standard catacombs-type area), the weald (woodlands), the warrens (kind of a mixture of stables and butchery), the cove (a dank coastal cave), and the Darkest Dungeon (which starts out as an evil cathedral before getting eldritch as fuck). Although there is some overlap in their bestiaries, each area has a general theme to its monsters, along with 2 unique bosses. The bosses all have their own unique gimmicks which are fairly fun, though most of them involve "can you deal damage effectively to the back ranks of the enemy formation?" to some degree.
Each foray into the dungeons can be short, medium, or long (plus one "exhausting" mission). This is randomized for the four main areas, with fixed missions for the Darkest Dungeon. Longer missions give you more chances to get treasures, along with chances to camp (taking a pit stop in a room to use some camping skills for various buffs and/or healing/stress relief, though there's a chance that a camping attempt will end with getting ambushed), though once you've gotten the hang of how to build a party, I wouldn't say the mission length is necessarily related to difficulty, aside from just managing to make the most of your limited inventory space. It's all quite nice and intuitive, although I feel like having fixed maps for the Darkest Dungeon missions works to its detriment.
After all, the game is supposed to be half-roguelike, which bring me to the next talking point: death mechanics. In short, once a character reaches 0 HP, they're on death's door, at which point taking any damage will have a chance of killing them permanently. It's honestly a more forgiving mechanic than it had to be, even with characters taking a big stress gain and getting a debuff when death's door is triggered. Yes, granted, sometimes you'll have the shitty luck of a character hitting death's door and then dying immediately from bleed/poison damage when their turn comes up, but you can also have streaks of a character surviving 3 or 4 hits to force their way through what would've otherwise been a lost fight. I feel like the mechanic tends to favor the player overall, but considering that it does take a fair bit of investment to work characters up to level 5 or 6 and upgrade their equipment and (useful) skills fully, plus doing stress relief in town and potentially some quirk management in the sanitarium, it's probably a good thing that there's a little margin for error before they die.
I've mentioned stress a fair few times without really explaining what it is. Basically, each character has a 100 point stress meter. In dungeons, various actions by both you or the enemy can raise or lower it, though for the most part, stress rises faster than it goes down, so you'll probably also make some use of services in the town's bar and cathedral to also help lower stress. If it reaches 100, that character will have their resolve checked, after which they either become afflicted (negative status that has a variety of bad effects depending on the exact affliction, e.g. selfish, paranoid, etc.) or virtuous (positive status that has a variety of good effects depending on the exact virtue, e.g. stalwart, courageous, etc.). Characters who're afflicted are an incredible pain in the ass, since they tend to spout random bullshit that gives everyone else stress on top of doing dumb things like skipping their turn or shuffling their position in the party or intercepting heals meant for other characters, which can all spiral out of control rather quickly into a total party death. Even if that doesn't happen, though, building up another 100 stress (for a total of 200) results in a heart attack, putting that character on death's door (or killing them outright if they happened to be on death's door already). The whole thing is basically a way of preventing you from grinding forever or constantly using the same few characters. I'm sure some people see it as Fake Difficulty, but I think it's pretty well-designed mechanic that accomplishes what it's set up to do.
The art direction for the game is quite strong, I think. I'm sure it won't appeal to everyone, but it's got its own style that it sticks to, and I think it looks good. While playing the game, it never stood out that there were very few animation frames (idle animations have more frames than most attacks), because it all looks pretty much exactly as it ought to within the overall presentation. It's a pretty good example of doing more by doing less.
The music is a bit more hit-or-miss. Each area has its own combat music, with the hot-blooded ruins music and strings-heavy weald music standing out much more than what there is to hear in the cove or the warrens. Still, for what it is, it does its job pretty well overall. The soundtrack isn't going to stand up to the likes of Digital Devil Saga or Valkyrie Profile, but few would.
So, I've said pretty much nothing but good things about this game so far. However, if I was to give it a rating, it'd be a B, since there are two big flaws that stuck out to me.
First, the game is a grindfest. Now, I'm no stranger to that, and to a degree, I think grinding is fine since it's all about making progress towards a goal. However, the grinding in Darkest Dungeon is a bit excessive. Grinding for hierlooms to upgrade town services, grinding for gold to actually use those services, grinding up experience to keep filling in the ranks where attrition strikes...it all adds up over time. I've heard that at least some of the grinding was reduced in patches after I'd stopped played, which I look forward to seeing for myself when I get around to playing with the Crimson Court DLC, but until then, I'll stand by my opinion that the grinding was overboard. It wasn't as bad as, say, trying to get rare chest items in Final Fantasy 12 (or fighting Yiazmat in Final Fantasy 12, which was its own grind), but it was more than it really had to be.
Second, the Darkest Dungeon has a couple of mechanics that are implemented poorly, especially in contrast to the quality of the rest of the game. First, any character who does a mission there gets a special status (indicated by a torch next to their name). This prevents them from doing any further missions in the Darkest Dungeon. Seeing as the game already had the stress mechanic to encourage using a variety of characters, adding this on top of it was unnecessary, and all it really accomplishes is inconveniencing the player. Second, skip the rest of this paragraph if you don't want spoilers, but the final boss will be triggered at two specific health intervals to do an attack which forces you (as in you, the player) to pick a character from your party to sacrifice. Putting aside that this was implemented so poorly that I'd thought the game had gotten hung up the first time it happened, this is a really dickish thing to do in a game with permadeath, and the sad thing is, it doesn't even make things much harder because the final boss is kind of a pushover. It was as if the developers wanted to give the final boss an instant kill that bypasses death's door, but then they balanced the whole fight around having only two characters, which kind of renders the instant kill rather moot (particularly when the player gets to pick which character is killed, so you can sacrifice whoever means the least to your current party).
On the whole, though, this was a pretty good game. Hopefully, the development since the last time that I played it will have made it even better. I'm reserving my final judgment until I experience the latest version of it, but until then, I'd give it a conditional vote of support.