Wave 1-6
(First of all do not buy the lightning or the rain upgrades because they do not work,they just steal your money and it will mess up getting to higher waves). Buy a "Mac10" after wave 2,they are cheap powerful weapons for the . Wave 5 starts to introduce aircraft that spawn zombies,kill them as quickly as u can but if u can help it leave an aircraft or two spawning zombies to earn some extra cash. Be cautious you may need to use a plow truck to help save from getting hit a few times,remember use one per wave till later because they only replenish once per completed wave. Start buying your Roof-men and your Shooting driver and as u buy them equip them all with a "Mac10". Wave 6 focus on killing the faster targets like dogs and faster runners,your Roof-man will take help and mop up the rest of them for the most part. Be sure to destroy the aircraft before they fly away from the way they cam in if u leave them for extra cash. Get your shooting driver and equip him also with a "Mac10".
Wave 7-12
Wave 7 you will have more than enough firepower to only have to worry about the street,your Roof-men will take care of everything else,even spawns from aircraft. After you fill up your truck-men fill the two slots on your copter,do not buy them any upgrades for now.
Wave 13-31
Cows start coming in,u don't really need to worry about them just focus fire on them and u should be fine. Save your money and get a "Bazooka" for each of your Helli-men,Next save your money to buy yourself a "Chain-gun" than your Truck-men "Chain-guns".
Wave 32-34
Cars start coming here you will need to look live as they are very fast and very strong you will need to use a Plow-truck at least once per Wave till 34,34 u may need to use 2 of them.
Wave 35
Wave 35 is impossible because the game is not programmed right from what i can tell for u to be able to pass all the cars that come on this wave,the lightning and rain that are suppose to help do not work,and the cars are too powerful and need to be nerfed,sorry guys