Game has 6 levels and as Cupcake shop vendor you win when you complete all six levels. Game levels are locked till you win the previous levels with appropriate score.

When a customer orders, you can fulfill the order by clicking on each item in customer order. When order is complete, tap on the cupcake to serve the customer.

Time remaining in the level and money earned in the level is displayed on top right corner

Each level you need to score required point to move to next level:
LevelRewarded per customer$ needed to clear level
110130
210100
31270
41580
51851
62044