This game seemed impossible at level three till i thought about a few things. 1~Try to not to summon until you can summon at least a few guys as a group, it helps maximize what minimal damage you have to work with. 2~ on every level i waited until the enemy was close and bought the salvage yard, then i just made A shovel guy, then 2 then 3 in groups until i had a good space in between me and the zombies to gain enough for another salvage yard, max those ASAP. 3~there is no reason to waste the airplane or harvester until you have a mostly full screen of enemies, since you gain yeeha(or whatever they are called) points for the kills of the airplane/harvester, its easy to gain gold during that time by using one, waiting for the screen to almost fill then using another. 4~get the priest ASAP once you have him its game over, i didnt summon anything but shovel guys till i got my priest out then i made a few shotgun guys and a errr truck guy with mounted gun thingy lol hope all that helps :)
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