Content warning for those troubled by vampire stuff.
I've been curious about this game for a while, if only because I'm curious about how different games give different treatments to the deck-building genre.
Dominion's simplistic-but-elegant system has you buying points into your deck, which are required to win but also interrupt deck flow. (mild content warning: there's a Witch card and a small expansion set of cards dedicated to alchemy, but you can include or exclude any cards you want; nothing but money and points are required.)
Thunderstone (content warning: some magicky stuff) has you buy cards into your deck but the purpose is to go fight monsters, which then go to your deck as points. Probably the closest to Dominion in gameplay but turns it into a dungeon crawl.
Ascension (content... warning? The thematic material is kind of obtuse) is what Dominion would be like if it were Fluxx. Whereas the previous two titles have particular rules governing the number of cards you can play/buy/attack per turn, Ascension is a lot more free-form: you have money points and punching points, and you can basically buy or punch as many cards as you are able to afford that turn. Also, punched enemies go into a common discard pile instead of your deck, so they convey a reward one time and are gone forever. And the available cards are not stacks of cards but one giant random pile with only six cards showing at a time. This means that gameplay is much more tactical than strategic; you don't know what cards are coming up from one turn to the next, and comboing cards is both more difficult and less prevalent. Also, it makes the four colored themes semi-meaningless.
I'm not sure how to describe Heroes of Graxia; it's kinda halfway between Thunderstone and Ascension. I just know I didn't like the gameplay. One point of note: you can attack other players armies on the table and not just baddies.
Josh and I have also played the deck-building cash in on the popular zombie video game franchise. The gameplay is not great but the theme actually made it more fun for us to play than Graxia. Still not something I'd recommend, if not for the zombie content, then just because it doesn't play very well.
So this brings me to Nightfall. We have demo decks at my gaming club but no rules were included and we haven't found anyone who has the game who can teach us. One point I liked from what I've heard, is that instead of buying points into your deck, you're trying not to take damage cards into your deck, which aside from being negative also slow your deck down like victory points. So it's my understanding that the goal is a low score kinda like golf.
Did I get this right? What more can you tell us?