Slay the Spire is a roguelike deck builder, featuring turn-based combat where you use cards to attack and defend.
Pro Intriguing world
Slay the Spire features a desolate land with just a massive tower called "The Spire" looming over it. No one knows why it's there, why it's inhabited by otherwordly creatures, and why heroes from far away are drawn to it. This makes progressing through the game a lot more interesting because you're gradually uncovering this mystery through the eyes of your character.
Pro A great mix of genres
A roguelike that has deck building might sound weird at first, but it's a surprisingly fun concept. You can select one of classes(decks), choose a path on the spire, fight monsters using your deck, get new cards to improve your deck, and even fight bosses. There's enough strategy, depth, and randomness in all of this, which can make it really satisfying when you make a great deck, win a difficult battle, or get extremely lucky.
Pro A pay to play card game
Card games usually are free to play, endlessly milking their players for money with new card releases and expansions. Slay the Spire is an exception, having only a single purchase that helps sustain its developers. This helps you to enjoy the game without worrying that your wallet is not thick enough to keep up with all the new releases. It also helps keep out trolls and heralds of the microtransaction apocalypse, which can feel really nice.
Con Some cards can feel impractical because of randomness
There a really good cards(usually involving exhaust and poison mechanics) that don't really work by themselves, requiring you to have another card for a synergy effect. If you only have one of the cards, it can feel like dead weight that hinders your current playthrough, making it even more frustrating when you can't find a matching card because of randomness.