Bolo: Overpowered. Compare to Lookout, one of the game's stronger trashers. A non-terminal non-mandatory multi-trasher from top of deck is already probably busted. The Journey token >advisor effect is just icing on the cake.
Sky & Wrench: Should care about whether the Journey token is face-up, not face-down. Just reverse the order of the effects.
War-bird Wrench: A bit weird to have an Attack that is on average probably good for your opponents.
Rottytops: Four different effects seems a bit much. It's a wordy card that's also difficult to understand and requires reading three other wordy cards, each with situational effects. I have a hard time judging power level or what I'm even trying to achieve by buying this card.
Jet Octo: I like it! Those two effects could potentially go on different artifacts, but that's not necessary at all.
Refreshed Zombie: I don't know about this one. The Duration effect is pretty cool, but -1 Action is awkward and Lazy... I will get to. Maybe you could make it a Night card and -2 Actions? Then you at least have a guaranteed(albeit difficult) way to make Zombie happen via playing 2 Rottytops at Night.
Lazy: This just doesn't feel like a very bad State to have. It just forces you to do Refreshed Zombie's treasure remodel every turn I guess? Additionally, the way to discard it seems unfun as it kinda just happens sometimes without much player agency.
Abner & Poe: This shouldn't have the Zombie type, that is reserved for the cards Necromancer puts in the trash. I like the effect, though!
Zombie Caravan: Considering this is a split pile, I think three separate effects is too many. Maybe cut the bottom effect and nerf the discount from the top one? This card could be fine honestly, but I'm unsure.
Plink: The whole decision card thing is not my favorite because of increased complexity and that reading the card doesn't explain what it does. Well anyway. Plink seems fairly strong for a 2-cost but not super busted or problematic.
Dash Newt: I like this artifact. Interacting with the bottom of the deck is a bit awkward but I see why it is the way it is next to Plink. Honestly, maybe you change it to discarding top of deck and cut Seer Dance effect B? Or try top of deck and leave Plink/Seer Dance the same just to see what happens?
Vera: Another very complex card. No I will not shut up about this. I would cut the whole Refreshed Zombie clause, it just feels a bit much(and I don't much like Refreshed Zombie
). The rest is chill and pretty cool. Many of the effects feel unrelated to each other but yknow. I like that you can use excess buys with Gastro Drill and Vera to churn through your deck.
Gastro Drill: Following the trend of cool artifacts. This one seems fairly strong, although that's less of a concern with Artifacts since they bounce back and forth.
Zapple: I'm a sucker for Duration effects so this is pretty chill. I don't think Spark Dance needs four different choices since you only ever get one at a time. I would cut effect D because it has serious tracking issues.
Bonker Tortoise: This is too good. Taking it is the only reasonable Spark Dance option. I would cut the trashing and +buy at least.
Harmony: She's fun. No complaints other than with Decisions in general.
Sea Frog: Cool and simple. I like it!
Shantae, the Half Genie: I talked about this already. Good lord. Taking two plays to exchange is too much.
Bubble Mermaid: Losing Artifacts kinda hurts. I might make this say "When you gain a card costing 4 or less, you may put it onto your deck".
Hover Bat: Other players gaining Victory cards usually happens later in the game which is exactly when you don't need to trash cards. Also, It's weird to get this off of Belly Dance since that usually happens early and it's so easy for other players to take Hover Bat before buying Victory. Not my jam.
Shantae, the Pirate: Pretty good. I like the Reaction.
Shantae, the Forgotten Hero: Long name. There are so many Genie Artifacts holy moly the analysis paralysis will be bad. I don't really like the condition because other players can just stop you from doing what you want with this card, which is worse than RNG in my opinion. Also, the next stage is an Attack so they extra won't want to play a Duration and help you.
Nega Shantae: This does too many things, which is extra egregious for a pile that makes you read so many cards. The exchange condition seems arbitrary and awkward.
Shantae, the Guardian: IMO perma-moat effects aren't very fun. The other effect is fun, but I doubt anyone ever sees it in actual play.
Tinkerbat: This is a good non-Supply card.
I wish you'd put the other Genie Artifacts with their paired cards and saved Shantae for the end. Well whatever. I'll get to them later,
Risky Boots: Wordy but solid. Again it should care about Journey token being face up rather than face down.
Dark Labyrinth: 6 different types is a really high bar. Most likely is Night, Victory, Action, Treasure... Attack and Duration? It's a lot. I don't like returning artifacts but it's whatever. Three artifact choices is a lot(I would drop Twinkle Harpy first) but whatever. The below-the-line text is fun.
Dribble Monkey: This is pretty cool but could probably be on two different Artifacts. Bottom half wants to come from a card that flips your Journey token, not one that can technically have Maze Mouse but is super difficult to have Dribble Monkey and Maze Mouse at the same time.
Maze Mouse: I like this one. +$2 is probably too much, though.
Twinkle Harpy: I hate it. It doesn't come from an Attack, and it's straight up not helpful to have. Exiling the top card of your opponent's deck is on average good for them.
Tinkerbrain: Lots of effects in one Project. Probably weak on tables without Night or Journey cards. With Journey cards it might be too much?
Pirate Master: This card is pretty fun. The below the line text is probably unnecessary and overcomplicating. Villagers and Tinkerbats probably don't want to be on the same card. This also somewhat scales with player count but isn't so bad about that. Those are all small gripes, though, and this has some fun decisions for whether to play Coppers or not.
Caclklebat: This card is fine except for how many Genie Artifacts there are.
Lonely Grave Island: The top half is probably too good for a $5 project. The bottom is fine but probably doesn't need to reanimate all the Tinkerbats.
Empress Spider: I like the wording on this one. On some tables, it's literally useless though. Probably shouldn't cost $1 'cause that just makes it a no-brainer buy sometimes.
Cackle Spider: This is a cooler way to gain Hover Bat. I only wish it was attached to an Attack instead of Empress Spider.
Giga Mermaid: Big fan of the art
She's a fine card but could probably be a duration instead of using Envious. I don't really see what the core idea is here but unfocused is better than nonfunctional. The bottom half is pretty unnecessary.
Twitch & Vinegar: Should probably be an Attack. The +$1 doesn't need to be there. This is a fun card though! I like the overpay, though that might make it too strong.
Seven Sirens of Paradise: Two Curses is brutal! It could be fine though. IDK about it referencing the Shantae cards, since they won't be there in basically any randomized games. The rest is pretty cool. Maybe this works out fine in playtesting?
Aaaaaand it's midnight. I will look at the rest later. Hey, throwing ideas against the wall is fun and so is criticising them. Thanks for posting such a high-effort expansion!
on top; if they want to keep the Bubble Mermaid, I say just don't put it on top.