Biomass is an action-packed game designed for Windows that thrusts players into a mysterious, deserted lab environment. Players awaken with no memories and must rely on computer logs from deceased crew members to navigate the challenges ahead. The game involves managing weapons, armor, and the biomass required for your cloning pod, all of which degrade over time. Players must strategize to find rare item drops to repair their gear and enhance their chances of survival.

As players progress, the threat level within the ship escalates, creating an intense atmosphere of urgency and danger. Upon death, players respawn as fresh clones, requiring them to retrace their steps through previously cleared rooms to reclaim lost gear. This mechanic adds a layer of complexity and tension, making each run unique as players confront the growing dangers within the ship.