Cassel Games, a leading Korean indie developer that has seen consecutive successes with its unique 'Rat' IP—from the deck-building defense of 'Ratropolis' to the economic construction simulation of 'Ratopia'—is back with its third new title.

'Ratocalypse,' featured at BIC 2026, is a new strategy RPG that combines turn-based tactics with auto-battling. Fans of Ratropolis should take particular note, as Ratocalypse tells the story of the world after Ratropolis fell to a zombie plague.

Players take on the role of Ramus, a prince of the fallen Ratopolis, and begin an expedition to drive out the infected and reclaim the city. The tutorial guides players through the process of defeating infected enemies near the outskirts and joining forces with other rats. From there, the game truly begins: players must manage their base, recruit an expedition team, and set off on a journey where the path ahead is shrouded in uncertainty. It is a harsh environment typical of the roguelike genre, where fallen team members cannot be revived.

As one might guess from this description, 'Ratocalypse' is heavily influenced by Darkest Dungeon. The opening scene, where the player recalls the fall of Ratopolis and writes a letter pledging to reclaim it, feels like an homage to the ancestor's letters in Darkest Dungeon. The hardcore sensibility is also familiar: the contamination that accumulates when you are hit by enemies or delayed on each expedition, the chance-based survival when taking fatal damage, the 'evasion marks,' and the agonizingly limited inventory. Even when an expedition succeeds, characters often return with lingering conditions, much like diseases.

However, 'Ratocalypse' differentiates itself by incorporating auto-battling. While other turn-based roguelike RPGs allow players to actively respond by carefully dictating every action, here, once you set your party's behavioral guidelines, you cannot modify them until the next rest period. You must play through an entire round automatically before you can change your tactical instructions. This demands a high level of strategic foresight; rather than reacting to the flow of battle in real-time, you must analyze enemy patterns, types, and your own party's traits in advance to craft your strategy. Furthermore, since you can only use one item per round, you cannot rely on spamming health recovery items to escape a crisis. This makes it all the more necessary to plan your strategy with your party's health status in mind.

Because everything unfolds automatically outside of rest periods, combat feels fast and satisfying when things go well. The game supports 3x speed, allowing players to enjoy that sense of momentum as they cut through enemies. However, when a sudden critical hit forces you to scramble, the game allows for meticulous planning during the rest period at the end of a round. You aren't just changing skill priorities; you can use up to three 'Tactical Points' to issue specific commands, such as advancing turn order, moving, or designating tactical targets. If it's not the right time for those commands, you can use the points to fine-tune skill activation conditions. These options go beyond simple settings like 'aggressive' or 'automatic,' allowing players to make decisions based on a target's HP, distance, and turn order.

As mentioned, when a character takes fatal damage, they have a chance to survive at death's door—and the beauty of 'Ratocalypse' is that the player chooses how to gamble on that survival. You might choose a 80% survival rate at the cost of increased contamination, or a 50% survival rate that clears all status ailments. Even after surviving once, you usually have one more 'coin' to spend, which allows for risky, high-stakes strategies to push forward quickly. Of course, bad luck can lead to the death of a party member or a total wipe, but the way the game allows you to return to your base and reorganize your expedition team after a failed run is a well-implemented feature of a hardcore roguelike RPG.

'Ratocalypse,' which further develops the world of those cute, iconic rats, is a title that proves Cassel Games' knack for unique gimmicks and system design by putting a fresh twist on a well-known format. As the game was presented exclusively offline at BIC and no release date has been announced yet, I highly recommend that interested players check it out at BIC 2026.