This illustrates the development of a family of tower defence games. The project is developed with Unity. It adopts an efficient way in the period of implementation, including how to build Gird Map, how to spawn enemies by using XML files and Excel, and how to make the path for enemies to move along. It also solves some problems in game development like how to scale all elements and adjust them to dierent screen resolutions, and how to implement a generator to produce games.