In this chapter, we enter the world of 2D game animation in Unity—specifically, sprite animation and its associated feature set, which is extensive. If you're planning on making 2D games, such as side-scrolling platformers or casual puzzle games for mobiles, or if you're creating animated GUIs and menu systems, then 2D animation will probably be highly important for your project.

A 2D side-scrolling platform game in action

Before getting started, however, let me elaborate further on the meaning of 2D, as opposed to 3D animation, to clarify the scope of this chapter and the kind of animation we are concerned with here.

By 2D (short for two-dimensional), I mean only a specific kind of presentation, that is, any scene presented using either an orthographic camera or a camera showing objects in a planar or flat way, not allowing the user to rotate their view and observe events from other angles. In this sense, even a 3D scene may be part of a 2D game because 2D relates...