For your project, you don't need to go into a lot of detail about the history and evolution of video games. However, you should still talk about it in at least 3 to 4 sentences. It'll be a good introduction explaining how your project connects to the real world. Also, you can include the results of previous, similar experiments done by actual scientists to support the design of your project. Here is a good one to look at (it has some advanced language, but it also has a great background): http://www.temple.edu/ispr/prev_confere ... borini.pdf
You should mostly focus on explaining background for the two types of controllers. For example, how are they similar, and how are they different? And always explain any key terms or concepts too. For your project, the key terms are: Control scheme, Industry standard, Natural mapping, and Peripheral. (I found them on the "Out of Control" project idea page: http://www.sciencebuddies.org/science-f ... p022.shtml
) If you come across any other words that you think are important, you can add those too. And also, try to give examples of games other than the racing one that you're using (like Wii Tennis, Wii Golf, etc.) You can even add examples that are not video-game related, such as how the knobs on a stove match up with the position of whichever burner it controls. (See picture below.)
If you didn't do so already, you should read over the guidelines of a project background: http://www.sciencebuddies.org/science-f ... plan.shtml
My teachers always tell me that it's better to say too much than say too little. So don't be afraid to add whatever you think is related.
If you have any more questions, feel free to ask; I'm always willing to help out!