If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Make burger to the customers as quickly as possible to earn the biggest money. The ingredients starting with burger base will be highlighted. Click on them in that order, and then click on the box. Click on the box again and give it to the customers. The ingredients will vary for the next burger. The number of burgers and the ingredients will increase in the subsequent levels, and limit will also in