Well, to get referrals is an important aspect of the game, but you also have other features to make it more interesting. First, everybody gets random referrals (all users are assigned to an upline). Secondly, some users may not be able to get enough antivirals, they will die and the antivirals will be distributed among other players. Finally, you have the Antiviral boost feature that is like a lottery that distributes an Antiviral Pot once a day.
I still haven't received an answer to my question..
~
If the levels and number of referrals can be infinite and your chances grow the more people sign up through your infection link, isn't this some kind of referral ponzi?
~
Referrals being an important aspect of the game means these who cannot get enough invited people deposit on your game have a smaller chance of winning. At one point, in the ideal situation of this game becoming super popular, there's going to be no more people to invite through a link as most/all interested players have already joined the game once. We also have influencers like youtubers who could gather thousands/dozens of thousands of referrals in no time. Will they not also have a large advantage in the game.. until the moment comes when there will be no more people using their ref link?
You can win without inviting people, because all players that sign up are assigned to a random existing players. Also you earn from any level of referrals, so imagine that an influencer invities a lot of people that become his direct referrals, but this influencer is also related to you in the diagram of infection, so you will earn amounts from all these new players. Also you can earn form the Antiviral boost. To win you need to a balance between having referrals and your antiviral power value. Also think about your target, that is the maxium you can win in a level. Also, players may create multiple accounts. Then you have the expiration period, so players will die and their amount be distributed again. That's why is called strategy game, read the rules carefully, there are multiple factors to consider in order to win.