In a future world that is highly technologically advanced but plunged into disaster, a horrifying bio-catastrophe erupts, turning the majority of humanity into rampaging bio-monsters, while infected organisms continue to spread and proliferate. Simultaneously, cities suffer immense destruction, and people find themselves in a state of panic and chaos. The player assumes the role of a biochemist who, at the onset of the catastrophe, becomes trapped in an abandoned laboratory. In this laboratory, the player inadvertently discovers a unique bio-virus capable of controlling and altering the genetic makeup of living organisms. In order to survive and find a solution, the player decides to utilize this virus, injecting it to enhance their own body, transforming into a cyber rodent to gain powerful abilities while maintaining sanity to combat the mutated bio-monsters. As the player embarks on an adventure in the abandoned city, they find companions to fight alongside. Together, they str...