The gameplay loop is tight and fast-paced enough that you can almost forget about the fact you're bringing people a hot cup of spaghetti. Nicely done!
I agree with the comments saying there's a bit too much running to do. A few improvements come to mind though:
- having intermittent breaks between customer waves to prep more drinks for the counter
- making the counter/shop smaller and faster to navigate
- Allowing the player to take orders from the front side of the register
- customer hitboxes being a little more generous
I did encounter an issue that isn't on your list, as well: If you have a coffee in your hands and you're *just the right distance* from the counter, pressing space will delete the coffee from your hands without actually setting it down.