The Last Citadel is a cooperative action game built around expeditions into a procedurally generated fortress that reshapes itself with every run. Players can face it alone or in a party of up to four, choosing from over 45 abilities to assemble a loadout of four alongside a suit and weapon before heading in. On higher difficulties the game shifts toward defined roles, with players taking on DPS, Healer or Tank positions to survive brutal encounters.
Each expedition layers on character progression through passives collected during the run, altering how a build performs as the session unfolds. The arsenal spans rifles, lasers, rocket launchers and melee weapons, all of which can be upgraded with unique modifiers and effects tailored to a team's needs. Cursed Weapons surface alongside drones that provide assistance and altars that modify weaponry further, feeding into a loop where adaptation matters as much as raw firepower.
The Citadel's Guardians serve as raid bosses, each carrying a distinct set of mechanics that reward players for learning their attack patterns rather than brute forcing through them. With the world generating new layouts and encounters on every attempt, no two expeditions follow the same path through the fortress. The Citadel keeps reshaping itself, and the loadout that carried a team last run may not be the one that saves them next.