The purpose of this game is to make all aliens happy
Each player has level of angriness.
Make sure you do your work fast to avoid issues with your clients. Game is self explanatory start by tapping characters and ships, you will see how they react.
An advantage of valet parking is that it is possible to pack more ships into a given physical space, in what is generally known as "stack parking." The valet holds all the keys and can park the ships two or more deep, as he can move ships out of the way to free a blocked-in ship.
In many circumstances you will need to wash ships, deliver alien-doughnuts or other to get a good tip. For example if you want to wash a ship, tap on the bucket! As An efficient valet service will implement (or at least prepare) a system to handle the expected number of ships and guests.