Wow. Finally got the impossible badge. START WITH MADAGASCAR! Otherwise you'll run into this situation:
"Mr. President, sir! It appears that a single man in Greenland is running a slight fever AND he SNEEZED!"
"This calls for drastic situations. Shut down our nonexistant borders and our single harbor. Nobody leaves. Nobody enters. Burn all the bodies. Institute Marshall Law. This is some serious s***."
Heroic difficulty has one weakness - bio, max out Vit and Str, and use Reform on teammates when necessary. That way, you can have them recover massive amounts of health in one go, and have them recover extra from your strength.
Also, after the VERY first battle, click respec. Your money will go to 0 (don't whine, you only had 7), but you will gain an extra 19 attribute points. However, I believe they disappear if you respec again, so be careful what you do.
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 "Sonny 2"){kind=icon}