To be frank the game is unfinished as after a couple of days of working on it I was disinterested in the idea, but was still a fun challenge and learning experience for the Brackeys Game Jam.
Quick summary:
If you gather poisonous mushrooms, there's a chance these are served to customers and they won't pay for their order and complain "they'll get sick".
As for the purpose of the restaurant view, I just found it funny.
Upgrades explained:
- More staff: Counter space is increased so larger area where customers can get their order.
- Increase mushroom yield: Each upgrade increases the number of mushrooms you get from each mushroom gathered.
- More mushrooms: Spawns more clickable mushrooms.