* Norfolk Island
* Christmas Island
* Cocos (Keeling) Islands
* Ashmore and Cartier Islands
* Australian Antarctic Territory
* Coral Sea Islands
* Heard Island and McDonald Islands
* Jervis Bay Territory
Would make it more challenging. NT and ACT aren't the only territories.
The Northern Territory has too low a population density to support itself as a state. The top answer on Quora has a good explanation:
Got the rest with no problems.
bit easy though i am aussie