IRSEN is a turn-based roguelite where your character fights alone against coordinated enemy squads. Explore procedurally generated dungeons, collect genes from defeated enemies, unlock new skills, and reshape your build during each run. Develop your character through the gene system: combine genes, form gene chains, unlock new skills, and modify their properties. Corruption builds up over the course of a run. The deeper you descend, the stronger its influence becomes: your character gains mutations, and full overload means death. In each squad, enemies perform different roles and act together: protecting allies; drawing attacks away from allies; healing the wounded; applying negative effects; finishing off weakened targets. The combat system rewards thoughtful decisions: target selection, action order, and effective use of skills determine your survival. Each run is built around adapting your character: experiment with builds; discover synergies; adjust to new threats. In the standard mode, you can reshape your build during a run using the Gene Lab, adapting skill properties to fit your strategy. In Iron Will mode, skill properties remain random: you must build around what you manage to find and adapt to the flow of the run. Turn-based battles against coordinated enemy squads. Build development through genes, properties, and skill chains. The ability to reshape your skills during a run. Procedurally generated dungeons. Growing corruption, mutations, and the risk of death from overload. Two ways to play: controlled build shaping or adapting to randomness.