One improvement
Nice game, a better version of the original.
One thing that would be a HUGE help in this game, is a statistic for the options. I'm not sure if I said that right, let me explain.
Like if I put my mouse over the "infect airport" option, a percentage would come up saying my odds of infecting the airport.
I think that would help because the user wouldn't waste their time trying to do something with a low probability of triggering.