So, I've finally gotten my hands on an IRL copy of the Nocturne, and have played about 30 games with 5 Nocturne cards each. Here are my initial impressions.
Overall - Overall, games seem to be sloggier. Which I like. Now, I said the same thing about Empires when Empires came out, the reason being trashing was weak (relative to Adventures and Dark Ages) and there were so many ways to get points by ruining your own deck (which I probably overvalued initially). For Nocturne, it seems to be sloggier because the draw is often limited, awkward, or inconsistent. And I really want to try all those Night cards, which are stop cards in the action phase. It may be that I am initially playing it incorrectly, but that's how it stands now.
Boons/Hexes - These are a lot of fun. There are definitely some boons/hexes that you are happier to see, but it never feels like someone gets way ahead just because of a single boon/hex. There are too many revealed in a game and it tends to average out. I think the most powerful boons are Sun's gift, Wind's Gift, and Earth's Gift; the most powerful hexes are Envy, Delusion, and Poverty.
Heirlooms - While the concept of Heirlooms is great, I think it's the cards themselves that make it amazing. Lucky Coin and Cursed Gold offer an interesting choice about how many silvers/curses you want. Pouch and Goat are great to have but maybe you don't want to rely on them because there's only one of each. The minigames for Magic Lamp and Haunted Mirror are fun, but not overpowered, so there's an interesting choice of whether to go for them. Pasture has me questioning whether an Estate rush can be good.
Bard - Bard isn't that bad. If you have space for terminal money it's great. Also, I wouldn't say it was too simple or boring. If all the boon text were on Bard itself we would complain that it was too complicated.
Blessed Village - This makes the village idiot strategy feel good, even though it probably isn't. I think you pick these up a bit earlier than you would normally pick up village, because the boons help even when the village effect won't help until later.
Cemetery/Haunted Mirror - From what I've seen of people streaming games online, I think people are way undervaluing Cemetery. I buy this card way more often, and I still think I'm undervaluing it. Thinning is winning.
I feel like I have been overvaluing Ghost. Sometimes it feels like it was a mistake to get it, because the opportunity cost was too high and it was too slow. In an engine, I don't want to rely on Ghost because it's only every other turn, so I end up building a deck where Ghost only gives me overdraw.
Changeling - It's a fun card, but I haven't played any games where it felt outstanding. I tried to gain a Prince once, but my opponent pointed out that I couldn't unless I played Prince without Princing anything. I regret not doing that.
Cobbler - A strong card. The player that goes for this seems to win every time, although that could be coincidence.
Conclave - Although strictly weaker than Festival, it's really strong at $4, because it lets you get them early on, when you need the economy. Then later when you need villages, you already have them.
Crypt - I thought Crypt seemed really strong, but I am reconsidering that view. Or maybe I just need to buy more until they self-synergize! The problem is that if you're drawing your deck, you don't really want to pseudotrash your treasure, and if you're not drawing your deck, Crypt is so unreliable. I think it's better than Treasury.
Cursed Village - I feel like this could create engines all on its own, but I haven't gotten a kingdom with the right support yet. It's good even without support.
Den of Sin - It feels great to draw those cards, but man, it's basically Caravan + Expedition. It can't possibly be as good as it feels. I don't think you should try to draw your deck with just these.
Devil's Workshop - It's a bit awkward that you don't get a choice of what to gain, but I still think this is one of the strongest cards in the set, because Imps are just so good. It's bad whenever Imps are bad.
Druid - The only time this seemed good was when it was the only trasher, and then the other boons were nice options. Otherwise I haven't gotten good use out of it.
Exorcist - Another card I thought would be strong, but I might reconsider. It seems like it should be at least as good as Raze, but it's slowed down because it costs $4, and you don't get Will'o'wisp until the next shuffle. I think you'd rather have a trasher that gave you economy instead of spirits.
Faithful Hound - One time I went for a Storeroom/Faithful Hound deck, not really expecting it to be good. The deck exceeded my expectations. Luckily I never dudded, although my opponent put up a good fight with Raiders.
Fool/Lucky Coin - Fool is good when sifting at the beginning of the turn is good. Which is often. Unfortunately my opponent seems to think so too, and then Fool turns into a terminal +3 boons, which isn't as good.
Ghost Town - I haven't gotten much mileage out of this yet.
Guardian - It's so bad, but I still buy them. I played a torturer game where I fell behind, but I ended up with 4 guardians instead of 9 curses so that was nice. Still lost though.
Idol - It might not be the fastest Curser in the game, but nonterminal cursing is still so good. And to pull it off, you need lots of them. It's ironic that the weakness of Idol (only even Idols curse) means that you want more of them. Boons are good too but the buy phase isn't the best time for them.
Leprechaun - I like how this card is useful in both engines (where you try to get wishes) and in big money (because of gold). Although, I think it's better for big money. Hexes seem marginal, and wishes often come too late in the game.
Monastery - Although on paper this is as good as forager, it feels weaker for some reason. I think it's a psychological effect of playing it during the night phase or something. Also it doesn't work with draw-to-X so much.
Necromancer - I'm always happy to have more of these, because then I could trash good actions and take greater advantage of them than my opponent. And if I have extras, zombie spy followed by zombie mason is fine. The only issue is the opportunity cost of picking them up.
Night Watchman - This is a great sifter, much better than Guide. Although it's not great when you're drawing deck. Either there are no cards to sift, or you cause a bad shuffle.
Pixie/Goat - Pixie is a star $2-cost card, and makes so that I'm never sad to hit only $2.
Pooka - I've seen online streamers buy this, and then crash and burn. My opponent, not having seen those, did the same. But I think it's actually a decent card, with the right support. Just don't open with it.
Raider - So, Raider is pretty much Gold, but if you're buying Gold you'd really rather it not skip shuffles. The attack part has its moments, like when my opponent stacked them vs my Faithful Hound deck, but in general it is very marginal.
Sacred Grove - I know that terminal money cards tend to be the lowest ranked ones, but as far as terminal money goes this is really good. The +Buy just helps it so much relative to other cards like Harvest, Mandarin, Counting House, Merchant Ship, Giant.
Secret Cave/Magic Lamp - Secret Cave isn't that strong, but one time I got a bunch of them as part of a Double-Tactician deck. I bailed on that deck when I realized my only trashers were Goat and Bat, but I wish I had given it a chance.
Shepherd/Pasture - I get mixed results when I play with this, and I'm not yet sure why. It seems like there are some situations where you want to pick up a few Shepherds and green really hard, but I'm not sure of the correct timing.
Skulk - Haven't used this too much. Mostly I get it for the gold, and then I exchange Skulk for Changeling or trash it.
Tormentor - I've bought this a few times in order to get Imps. I've only ever gotten 2 or 3 Imps. Well, Imps are good, so I'm satisfied with it.
Tracker/Pouch - I think it's stronger than it looks, because boons are powerful and topdecking is particularly good early on. But let's not get carried away, it's a terminal $2-cost, it can only be so good.
Tragic Hero - I love this card! Not that it's particularly strong, I just like it a lot. Once I tried deliberately trashing them (with Ghost Town) on the theory that I wanted Gold in my deck. It turns out that no, I'd rather keep the Tragic Heroes if possible.
Vampire - It's weaker than it looks at first, because it's just so slow. If you buy Vampire instead of some other $5-cost, it delays that $5-cost by a shuffle, and you don't get additional $5-costs for another two shuffles. It's still really good though.
Werewolf - This really feels like a smithy-minus to me. Drawing cards is way better than hexing is, so it seems like you only end up hexing a lot if you are building your deck poorly.