To get the Mad Scientist achievement (in-game), do NOT destroy all cities. You have the option as you are playing to manually end an infection. In the lower right corner (inside a city), next to the Sound button is a Skip button (X). Watch the upper right corner, where the citizens killed/total citizens show. Close the city before you kill everyone. Repeat as needed to increase your cash until you can afford all upgrades.
I agree with truto Alasca dosen't exist (here or in the real world). Also, Alaska is not affiliated with the United States in Infectonator, but considered part of Canada. I guess by the time this zombie virus starts to spread, we'll see some shifts in allegiance and geography.