This game is really good! The gameplay is you will play as a small virus that must spread across the globe bringing the whole world into a pandemic and eventually extinction. You can power up your virus every time you collect virus points. These virus points can be used to evolve your virus and improve its adaptability.
You must keep up the strength of your virus because countries will eventually make a cure that will fight your virus.
Overall, the game is really good. Replayability is there to try other types of strains and difficulties. Highly Recommended.