While we did not create a full physics engine, we did go over some simple techniques to give actors interesting movement. Our discussion was focused on projectile-based movement and included bouncing, jumping, firing, and particle effects. Until now, we acquired a number of creative program techniques that enable us to create a wide variety of animations, simulations, and games. However, creating a fun interactive experience is not trivial. In the next chapter, we are going to learn about game design and a process for game development that will help us create amazing interactive experiences.