Overall a pretty decent game.

In this day and age, the question on everybody's lips is probably "Is it as good as Slay the Spire ?".
The short answer is no, as usual. There's a noticeable lack of variety in events and relics, which fortunately doesn't make Roguebook too repetitive, but we are far, far away from the potential game changer at every corner.

Also, despite the modest amount of time I've spent playing it, I can already tell this game takes the "block the damage, deal the damage" formula in a much more straightforward fashion. Notably, the majority of allies (who kinda behave like powers) are just plain offensive ones, and there's just not that many clever synergies and ways to deal with threats other than defending and punching them in the face.

In terms of balance, that means in higher difficulties, you're very reliant on luck to find the good damage and the good blocking cards. And, franky, not much else.

BUT

That being said, the game has a lot of good things going for it. The artistic direction is just lovely altogether, and despite what I mentioned above, it's definitely not the tragedy you might suspect in terms of gameplay.

Being able to bring two characters to the adventure is pretty interesting and very well handled. There's many, albeit basic, synergies between them, and being able to draw from both pools really gives you a lot of possible directions. Also, constantly swapping them to control which one's taking the damage and benefit from position-related effects makes for very dynamic gameplay, while also requiring careful planning.

The ability to collect and socket gems into your cards to give them extra effects is another fun twist in deckbuilding. It's not ridiculously strong like in Monster Train, or amazingly rich like in Wildfrost, but still arguably a plus, compared to a more linear upgrade system.

Also, you get to choose a passive bonus every few cards that you add to your deck. It sure is discrete, but I think of it as the most brilliant idea the devs had. Giving a little something (occasionally a huge thing) to make up for the loss of consistency and rewarding players for not tunnel visioning into the same strategy every run feels like a wonderful idea.

All of that, and the fact that each character has a respectable amount of cards and available strategies, makes Roguebook a very enjoyable ride.

On the negative side, not getting to choose a path and progressively revealing portions of the map simply feels like false depth to me. At the end of the day, you're doing the exact same thing as in all other deckbuilders, which is choosing between easy and hard fights, big and little rewards, Safety or risk, now and later. It's the exact same train of thought, and pretty much the same result. You just spend a lot of time going to and fro and trying to figure out how you can turn the upcoming sequence of events into something you're comfortable with, which these games usually do for you, by presenting you with a choice of paths. Given that runs are quite long, I find the unnecessary tedium annoying.

Also, poor optimization, and occasionally inaccurate damage previews.

Still, not a bad game by any standards.

That's it! Hope that helped. :)

Amazing, I spent hours and hours in this - love the world!

I wish there was an intermediate rating I could give this, because there's nothing spectacularly bad about this game. But there's nothing spectacularly good about it either.
The theme lacks unity. The Roguebook is a book, so you use inks and pigments to fill it in with your brush. Combat is played with cards, which have sockets that can be upgraded with gems -- which is distinctly not how playing cards work, and also nothing to do with the book metaphor. And then Treasures are tangible items, the magic weapons and tools you're carrying around, which you also use to fight monsters. It doesn't add up to anything coherent and leaves me confused about how the game world works. For example, there's two items on the overworld which appear as slightly different scraps of paper, and which mean unrelated things -- one indicates a random event with a choice to make, and one is a metagame currency that gives you upgrades between runs. Yet they're both paper, because... book? It doesn't mean anything.
The overworld's exploration mechanic is a major novelty of Roguebook, but it feels little better than a grid of lootboxes. I imagined I'd be writing new terrain into the book with my calligraphy brush, shaping the world to my will. No. You can reveal circles and lines, and what shows up on the revealed tiles is random. The strategy is limited to positioning yourself so that as many useful tiles are revealed as possible (there's even a helpful UI element to count how many tiles you'll reveal). There are certainly pre-revealed locations you can build towards, and pre-marked obstacles you can't pass through, but neither of these add enough decision-making to make it interesting.
The characters look and sound amazing. They're intricately animated with special gestures for particular cards and statuses. They have a variety of voice barks for everything from short grunts when they get hit in battle to entire sentences on finding a rare item and bragging about defeating a boss. And their character design is full of personality yet clear and readable. Not to mention the lovely background art, and the reactive music that grows more intense as you lose life.
The setting... exists? Considering it's diagetically inside a magic self-rewriting book, I'm not even sure of that much. The first area is a forest, the second is a floating island in the sky, and the third is a city. They all function in exactly the same way. The playable characters don't have any particular motivation for being here, they're not from these places. It's not clear that anyone worth mentioning lives in the city area. The enemies all dissolve into blue inkclouds when they die, so I assume they're not "real" either. There's no sense that any of this means anything, or even continues to exist when you look away from it. The worldbuilding (such as it is) is only as an excuse for the players to get in fights. It is allowed to present pre-written cool moments and pretty images, but then it must get out of the way so we can have gameplay.
Gameplay which will be alarmingly familiar to Slay the Spire players. You start each turn with 3 energy and 5 cards, and you choose to spend them on some combination of attacking, blocking, and investing in future turns. Block (it's called that) will reduce the amount of damage you take this turn, but excess Block is wasted. The core loop sits there, completely unchanged.
The big new idea in combat is the ability to Swap your characters around. Block is shared, but only the front character will take unblocked damage. When a character gains Block, they move to the front if they weren't already there. Other than that, many cards and treasures interact with position in different ways, such as being stronger or cheaper in front or by force-moving to a particular place. It's a very polyvalent mechanic that is used to great effect by each character and really forces your two characters to work with each other. It also feels distinctly like something that could have been done in Slay the Spire's engine, like a mod trying to account for the fact that most enemies aren't designed to fight more than one character. Rather than invent a new combat system that works for multiple characters, they just took the single-player combat system they had and tried to make switching between two stances feel like controlling two characters. And they did that very well! It works!
Roguebook fundamentally doesn't grow beyond its inspiration. It does improve on it in small ways. You don't get extra energy for beating a boss, so the way that high-energy cards become easier to play in Act III than Act I is gone. I always thought that was awkward. The cards don't have Attack or Skill written on them, so there's no more ambiguity between "playing an Attack card" and "attacking an enemy". Roguebook simply has some cards that deal damage and some cards that gain block. Powers are partially replaced with Allies, of which you can only have six in play so you're not drowning in icons reminding you that you're Intangible 2, Weak 4, Accuracy 6, Dexterity -1, and ten more things. Other Powers just become cards with Dissolve, as they always should have been.
Deckbuilding-wise, the extra upgrades gained by having a deck of a certain size encourage you to seek out cards to add. Card removal seems to be gone anyway, so the only way of having to draw less of the underwhelming Strike and Defend cards is to draft better ones. In short I am much more excited, especially in the mid-game, to take the exciting and interesting cards I'm offered, and I don't worry about diluting my deck with them. That's great, I'm rewarded for playing the game.
The idea of playing two characters and combining their draft pools is a very deep one, allowing for a far greater variety of builds. The characters' signature mechanics are a little complex -- I'm looking at you, Seifer, "when Seifer gets 25 rage his next card will use its empowered mode" implies that every one of Seifer's cards has a unique alternate form. Still, what can you expect, when the Ironclad and the Silent have already picked all the mechanical low-hanging fruit.
All in all a lot of little imperfections from Slay The Spire are removed.
The combat itself is balanced without being predictable. The basic strategy triangle of damage/survival/scaling is twisted into many new and interesting shapes depending on the characters you play, the enemies' special abilities, the cards you draw, the cards you draft, whether you choose to explore a level fully or save your inkbrushes and fight the boss early, the chaos factor of random events... I find myself repeatedly thinking I've discovered a game-breaking combo that surely couldn't be balanced, only to find that the next enemy is still somehow Just Hard Enough To Really Challenge Me.
From the many tantalizing menus that are still locked to me, I assume there's plenty of extra game modes and run modifiers to play with. No lack of content that I can see. And of course it's all gorgeous to look at and listen to. And it's fun to play! It really is!

Roguebook is an extremely competent execution, on every level, of an idea that's already been proven to work repeatedly. And... I just can't enjoy it, because I'd rather be playing more Slay the Spire.