:) Hi there and thanks for the compliments.
In regards to your question, it pretty much depends on the institution you are looking at. Different colleges have different names for the same thing . "Diploma of entertainment design" sounds so broad, it could be about anything. Depending on the path you want to take, you should probably look at contents of the course. Look for something that teaches 3D skills (MAX or Maya), Photoshop, and offers concept design and general art classes, with animation as a plus. However, be careful. If it is not really your passion (if you do not spend hours daily sketching on paper, sculpting or trying to figure out "how did they do it" already) you might find yourself learning very little in the course itself and end up with a decent chunk of debit and still be unemployable. Some courses focus on "academic" side of things and encourage their students to "dream and explore". They are mostly useless unless you want to become an essayist or art critic. Look for one that teaches solid skills that you can use. If you can control your own focus, you can find a lot of tutorials and free educational material on the internet already, and try and see if it suits you before you commit a couple of years of your life to it. However, if it is not already your passion, it will quickly become a chore once you try to work in the industry and you will end up hating your life eventually :)
I hope this helps,
Cheers and best of luck with your education,