I find that with the aviators, it's better just to fly straight up. If you have some height, you'll get into the clouds, allowing you to get a Sweet Impact, which both gives you lots of money and speeds you up quite a lot.
After not buying anything except the first start tump (for the game to be a bit playable), I saved all my money to buy the secret upgrade. Then I bought it out and found out it was toilet paper. That was when I stopped playing this game........
The game overall is half way between a shooter and a launcher game. I think that is why it is pretty good. One think you may want to add is a speed gauge. I feel I'm going faster when I get the power-ups and stuff, but a small speed bar like the stamina bar would be nice.
Pretty good game, but towards the end my zombies were so strong I could destroy every city by infecting a single guy with a click, and I had a really hard time getting the Mad Scientest badge because I couldn't earn money because all theo cities were destroyed. I had to keep skipping the final city just before I destroyed so I could play it again for money. There should be an alternative game-mode for this I think.
terriffic game, shows in such a meaningful way that the thing you fight for passionately may just leave one day, and how the only thing that doesn't change is change itself
 "Billy the Pilot"){kind=icon}
 "Burrito Bison Revenge"){kind=icon}
 "Rocket Toilet"){kind=icon}
 "Epic Battle Fantasy 3"){kind=icon}
 "The Birdinator"){kind=icon}
 "Infectonator : World Dominator"){kind=icon}
 "Gray"){kind=icon}
 "Factory Balls 3"){kind=icon}
 "Balloon in a Wasteland"){kind=icon}
 "GeoSketch"){kind=icon}
 "Medieval Rampage 2"){kind=icon}
 "Huje Tower"){kind=icon}