Airservices Australia Psychometric Testing

[CLAMES]

The course/job is not about the theory- you need to have it, sure. However, it's the sim where you do the real learning and find out if you can do it.

Warren,

Ferris is 100% correct. You can do yourself a disservice trying to learn volumes of theory without having an instructor to help you relate it to practice. When it comes to simulation you will have very little advantage over someone who has learned the theory in a structured way - on course.
Learning ATC is no different to learning to fly an aircraft, all the theoretical knowledge of how to do it in the world does not teach how it is actually done. Could I suggest you look at ATCX at www.visualvectoring.com or on YouTube. It is designed in part for people like you (and I declare I am a co-developer) to establish their aptitude for ATC and to get a headstart at skills development. It is a link between ATC gaming and training.
When you do get to the Academy you will find the experience challenging and exhilarating, and at the end of it you will have the best job in the world. Good luck.