Madagascar is easy, all you have to do is upgrade the infection chance before you upgrade any other category. Then, your virus, will spread to Madagascar quicker.
It's a little annoying to see people somehow cheating by finishing the race before they even cross the finish line, I have seen so many people do this trick, I even made a track (figure eight) where the all time leader cheated without finishing. So nobody else in the game can beat it.
Why do the troops automatically retreat, that doesn't give the player the freedom to do what they choose, I think it is a really good game, but the auto retreat thing is kind of dumb.
There is no originality in this game, it derives from three different games: Metal Slug, Indestructo Tank, and Indestructo Copter. Stop stealing other ideas and morphing them to look like your own.