Dude and Zombies is really not that hard. Here are some simple tips:
1. When a Zombie is cornering you while you're reloading try to jump over it. If there's a swarm of them, proceed anyway was you won't take too much damage from simply running into them for about half a second.
2. Focus on Exp. and Money upgrades first. Then Med-Kits and Health. Then Accuracy and Reload Time. Focus on the car last as you can work on that between waves.
3. If you are stuck with the Pistol/Revolver for a while, simply abuse Med-kits and mines.
Once you get the first shotgun and then on, the game is a piece of cake.
