It took me a while to do the first few levels... Then I unlocked the Flame Thrower. If you want to fly through the game, that's the gun you should use :)
A tip for people who get sick of dying by bullets/explosions - If you have been hit by a carpet bomb and your screen is flashing an opaque red, stop the car in a isolated area from zombies/soldiers and wait, your health will slowly regenerate. It makes a huge difference =)
It's a good game and all, but the only thing I dislike is this... When you bump into a car, you lose speed and they gain it, fair enough. However, why does this not apply when the bump into you? When they bump into you, you slow down and the speed straight past you. I lost a race because of this.. Overall, 4/5 =)
Must say.. He's a pretty durable Cactus. I mean, surviving machete and axe attacks? The Indians would have been screwed trying to get water out of that cactus on the Great Plains...