The goal of the game is to keep the hotel's guests happy so that you can gain popularity and make enough money to move on to the next level. The faster you serve, the more fees you get, and the more popular your hotel becomes. But, if you take too long, guests will frown, get up and leave. If you fail to earn enough money, you lose and have to play the level again.
To make your hotel popular, you should invest into its upgrades. Buy new items of furniture, coffee-machines, pictures, telephone to attract more customers.