Press [Ctrl] + [Shift] + [F5] to enter Developers mode.
Get a 3-star rank in all available dishes using the these recipes .
Purchase all the tables for your small restaurant then make deals with enough people so it becomes full. When the restaurant is full, you will not be able to start a trading dialogue with the next customer in line.
The Golden Scythe is obtained during the storyline. After the professor appears and you have lured a zombie onto the treadmill, you will be given the Golden Scythe to cut the grass that is growing on the graveyard.
Go to the island where you met a friendly cow after you built a bridge. Dig around to the left of the path that runs over the bridge on that island.