500000！ This is not just a number, but a once fresh life! That equates to 196 people per hour, or one person every 18 seconds. Covid-19 has caused a great disaster to the world. Against Covid-19 is a co-operative/ Solitaire PNP game, players fight the virus by adjusting the defense level of each region, organizing more medical personnel, developing medical facilities and factories, producing medical materials and treating infected patients. Although the high defense level can effectively control the spread of the virus, it will also have a huge impact on the economy, which is also a problem for players. Now let's start the challenge！