You play as a microbe on a "giant" "earth-sized" (regular size, to humans) petri dish. In this universe, humans are still just weak humans. But you are a mutated microbe, advanced beyond compare. Your altered DNA transmits to normal bacteria, fungi, and viruses, making them anthro as well. Only microbes can "exist" on the petri dish. Your "world" is apart of a young college girls science project. Time runs much faster for microbes than it does humans.