Rather surprised this game hasn't gotten a thread here yet.
Slay the Spire is a Rogue-like Deck-Building card game currently in early access.
You make your way up a monster infested tower level by level, fighting a boss monster every Act (3 total). So, rather light on story. But it makes up for it in mechanical fun and each run takes only an hour or two to finish. And, like many rogue-likes, it is the particulars of the run that make it interesting and replayable.
This is very much a Deck-Builder in a pc game. For those that are not aware of the board game mechanic, a deck-builder is a mechanic where you start with a small set of core cards and then modify that deck as you play, adding and removing cards to try and build an effective set of cards to use. In Slay the Spire there are two characters, the Ironclad and the Silent. Each has their own unique set of cards to play with (both starting decks and the cards they can add during play). There is a third class planned, but no information about them is available yet that I have seen.
In addition to the decks, there are also Relics that you pick up that will alter how the game works for. Some of these are minor, others can completely alter your strategy. Each class starts with a Relic that helps define how the character plays. The Ironclad has one which heals him for a small amount after every fight while the Silent has one which gives her more cards in hand at the start of every battle.
The game works by having each 'floor' of the spire be an encounter. These can be Combats, Events (which generally give you choices to make that effect your health or deck), Shops, Chests, and Camps (where you can heal or upgrade cards in your deck). Each acts also has several paths you can take up the spire. Some will meet up or branch off, others might be a narrow line all the way up to the boss. But picking what path to take (and what combination of combats, events, camps, etc you encounter) is a very important part of the game.
In a combat, you have only a few basic stats and your deck to work with. You have your health, your mana, and your cards. Mana is what lets you play cards, with each card having a cost from 0-3. By default you have 3 mana to use each round. You then draw a hand of cards (5 by default), play the cards you can/want, then discard the remaining. Repete the cycle each round as you fight the monster(s). When you can't draw any new cards your discard is shuffled into a new draw deck and things continue until you or the monsters are dead.
At the end of most fights, and often from events/shops/chests, you will be given a choice of cards to add to your deck. This is about half the strategy in the game, since what you have in your deck and how well things work together is critical to succeeding. Sometimes the best choice is not to add a card at all, since the more cards in your deck the less likely it is you'll get the ones you want when you need them.
Overall, I've been having a blast with it! Makes a great short session game and even unfinished as it is I've gotten 60+ hours out of it.
Sheesh, didn't realized I'd played that much.