There's a lot to say about this game, but it's best summarized as "Slay The Spire if it had balls".

The balancing in this game is pretty good. It takes a lot of inspiration from "fun but not-very-good" decks from Slay The Spire, and leans into them more to make them actually good (like Shivs, Claws). This game learned from Slay The Spire's weak points and refined it. Make no mistake, LBoL a pretty shameless Spire clone, but it actually manages to be better than Spire in many ways, so it gets a pass for that.

The biggest selling point of this game is the colored mana system, which not only makes you think about your energy a bit more, but also lets you nudge the random card reward pool into a direction of your choosing after every boss, letting you dynamically shape both your deck and your potential deck throughout your run. Every boss relic is also an energy relic, but they each come with a different added mana color (rather than +energy and an unfun downside), and you can only find cards that match the mana colors you have, letting you guide the direction that you want your deck to take. You also get to dip into other characters' card pools after the act 1 boss, so the deckbuilding variety gets absolutely crazy in this game without being overwhelming.

Even without all the Touhou aspects, this would still be an excellent roguelike deckbuilder game. But if you're a Touhou fan, the Touhou-inspired themes and characters are perfectly meshed with the actual game mechanics, and the game has a good soundtrack to boot. Truly a 10/10.