This is still in early access but it might interest some people, and there's no review yet! A shame!

9 Kings describes itself as "a fast-paced roguelike kingdom builder". Your job is to build a little town by playing cards. Some cards represent troops, some are defensive towers, some are stat-boosting buildings, some cards are enhancements for the units already deployed, or have more complex effects. When you have two cards left in hand, a battle starts: an army will come and siege your town. The battle resolves mostly in autobattler style, although you also have one special base building that provides an active spell-like attack.

The title refers to the 9 different rulers that fight across the kingdoms. Each ruler has a specific theme, with associated card set, perks, and main building. You'll play one of these kings, but you'll also encounter the other kings on the battlefield. When you finish a battle against a king, you select a new card out of an offering from their card pool. This allows various synergies and builds to emerge. Along the way, you can declare war on one new king and make peace with one king you are at war with, which thus influences both what type of enemy units you'll encounter and what cards you will be able to access yourself.

Since a battle starts when you have two cards left, and you gain one card after a battle, you'll usually play one of three cards in hand between battles. This is a fairly straightforward decision of which card gives most value when played now vs later. Every once in a while you'll have more cards in hand, due to buying cards at merchants or the effects of a card or a perk. It's usually still fairly straightforward to figure out the best play given what you have in hand though.

There's some metaprogression: when you repeatedly play a king, he'll gain experience that can unlock new perks, which are bonuses selected at the start of a run. I don't think any new cards are unlocked by metaprogression.

One other game mode is currently implemented, and that's the quest mode. This gives you various premade scenarios which are sometimes utterly ridiculous. Honestly this mode might be the better part of the game as you'll need to understand everything given to you and find a way to make a build work, while the more open roguelike variety allows you a bit more to lean on similar strategies all the time.

9 Kings is fun for a while but it seems that most winning stragies resolve around the same concepts. You find a way to increase stat A (HP, units, gold, whatever) each turn through some production building. You combine this with a way that turns an increase in stat A into a stat B multiplier (usually combat damage or attack speed). Thus damage multiplies each turn. Boom goes the other army. So yes, 9 Kings is definitely one of the more interesting roguelite games, but tactical play goes a little bit out of the window, defeated by the power of the exponential. The more of these type of games I play, the more I appreciate the fine balance in Slay the Spire..

However do take a look if the combination of town building / autobattler / roguelike sounds good to you!