It would be nice if the Upgrades are better sorted or maybe if upgrades are in two categories, the one that cost money and the one that cost angel investors. ;)
I won at stage 1-3. That was hard enough but then I played the 4th stage. It´s not impossible to win. The Zombies are too hard! And heres a tip for stage 1-3: buy a salvage as firstt and then only coubles of 2 shovel mans any time. try to get max salvages then the fram house and then only angry farmers and use the angry mob if you can. Anytime you need buy a trailer but since the farm house only 1 or 2