Adding particle effects

The game itself currently works, but it could use some more polish. One of the things we do to increase the polish of game is make use of particle systems; let's get started:

1. First, select the Player in the Hierarchy window and right-click and select Effects | Particle System.
   This will make this system a child of the player, which will be good for what we are going to do.
2. Change the Start Speed to 0 and the Simulation Space to World.

3. Open up the Shape section by clicking on it. Change the Shape to Sphere and set the Radius to 0 (it will automatically change to 0.01).
4. Then, change the Start Color to something to make it easy to see, such as purple:

This is a step in the right direction.The particles are now following the player, but there's still a number of things we can do to improve this.

1. Instead of just a single color, we can change...