Thanks to everyone who contributed! Other than general quality stuff, I tried to judge the cards in large part based on how important to the design it was that the card is a Victory card, and how well I thought it would fit in Renaissance, both in terms of simplicity and using Ren mechanics.
Parade: The condition to gain Parade seems like it would be met in two types of decks: strong engines that can draw a lot of Treasure payload using relatively few Actions and "good stuff" kind of decks, where you're maybe playing a few Peddlers and a couple of Treasures to buy this. I think it's an interesting challenge for the engine but maybe being able to gain this will be too luck-driven for the second type of deck. I like how the gain condition being different from Grand Market's opens up different methods to cheat it.
Polymath: This seems well balanced; it should be fairly easy to get up to 3-4 VP most of the time and occasionally it'll be really centralizing (which is good, in my opinion.) I like it a lot; my only reservation is that the amount of counting and deck tracking you'll want to do to optimize it will make playing with it could be a bit of a hassle.
Parliament: This is a really nice design for an Action/Victory I think, with a top half that does something interesting but which would be hard to price as its own card. The idea of having "disappearing victory cards" for a draw-to-X deck is also neat.
Pirate Island: This will naturally be worth 5-7 VP most of the time, with 8 readily achievable. It feels like something in between Fairgrounds and Colony, and compared to either I think it's too expensive for what you get out of it. I prefer the Fairgrounds approach of being cheaper, but requiring more effort in deck construction to get full VP value. Having Pouch as an heirloom to ensure you can always buy it is a nice touch.
Residence: This is similar to Recruiter at first blush, but while Recruiter is a crazy good card that I almost always get Residence is much more tactical, which is intriguing. I like the idea of getting a bunch of these and then blowing them all up in a chain reaction (although maybe that's not actually "good").
Farmstead: I like this concept; I think it's different enough from Banquet to be a good idea. I'm just worried that in its current form it might suffer Banquet's fate of being ignored most of the time; it probably needs to be souped up a bit somehow to really make it playable. Maybe it would work as part of a split pile with a good TFB card underneath?
Art Gallery: The top would fit in Renaissance, but I don't think it needs to be a Victory card. Probably it would be fine as a plain Action for $3.
Gallery: Very solid design which could open up some good tactical decisions in the endgame. I like including an Artifact as I think they were maybe a bit underutilized in Ren.
Tulip Field: Very well done, it ties VP to having tokens without getting out of hand, and I think the bottom half provides an interesting, unique way to get tokens. Maybe it can get a little bit crazy, but you need a lot of draw support for that to happen, and Renaissance definitely has some very powerful cards in it.
Paper Mill: This has a lot going for it; I really like the setup condition, and allowing other players to block with their own villagers without needing to gain Paper Mills is a good approach. The worry about endless games is real, especially with the Recruiter/Treasurer combo, but having to actually keep the green cards in your deck to get the VP alleviates some of the concern. I think I would much prefer 1 VP/Villager, which makes it crazy with a lot of Ren cards but also would mean it actually gets bought in games without another way to get Villagers. The bit about it having a minimum VP value of 1 seems like a needless complication.
Promenade: I appreciate the simplicity (and the attempt to make a half-Harem work) but I think this is a bit weaker than Coin of the Realm and wouldn't play significantly differently. The 1 VP doesn't add very much to the card in my opinion.
Construction Site: This is a really creative and cool idea. I don't really think it's a Victory card though, I see it as a Victory card gainer. I think something like this could work better in the vein of Distant Lands, as an Action you play and then set aside until the end of the game (maybe gaining an Estate or something at that point to keep the stop card in your deck). That neuters some of the potential for degenerate rush strategies (I do enjoy the occasional degenerate rush strategy, but I think Construction Site might make them too strong) and makes the card more fair if you're gaining a bunch at the end of the game. That all being said, the concept is so interesting that it's definitely a contender.
River: I don't think the world needs another Great Hall, this time with a bonus that only helps a pretty narrow set of strategies.
Stock Exchange: I think this swings too much from being too strong with other Coffers-gainers around to too weak on its own. I'm not really a fan of giving VP for Coffers, I think VP for Villagers is a more promising route. When you're stockpiling Villagers you can still use the rest of your deck to buy Provinces or whatever, whereas a Coffers-focused deck (especially a Baker stack) might find it never beneficial to work towards ending the game once it's set up.
Senate: The top is promising but the bottom is low-impact and wordy enough that I think it would be better as a pure Action.
Oil Painting: I am a fan of the setup clause; I like the idea of playing a game with 3 Projects available but you can only buy 2 more than getting an extra cube though. Projects are good enough that this will usually be worth at least 3 VP, but I don't think having a Duchy available for $4 breaks anything in particular.
Frontier: Interesting concept. It feels like it would be too slow at $6, but maybe too strong at $5? It's difficult to gauge since it obvoisly gets much worse if the player to your left also gets a few.
Caretaker: Kind of like Shepherd but for Villagers rather than draw. I like it, but it might need a more compelling reason to be a Night card (like gain-to-hand).
Subversives: Good design for a VP from Villagers card. I think the rate at which you'll be able to acquire Villagers is well balanced. Villagers are generally so good that I don't think this is going to provide much VP (except with Recruiter).
Kingswood: I'm not sure 7 VP for $7 is enough extra value to make you jump through that extra hoop of building an engine that produces mostly Coffers.
City Hall: This is pretty much an Acting Troupe which junks you and helps your opponents. Acting Troupe is pretty weak, so I don't think this is going to be strong enough to see much play.
Lots of good options! There were two that really stood out to me as being exciting ideas that needed to be on a Victory card, and out of those two one barely edged the other on the basis of feeling more like a Renaissance card.
Winner: Tulip Field by NoMoreFun
Runner-up: Parliament by Gubump