Australia is not a continent. Australia is a country within the sub-continent Australasia of continent Oceania. I'm not asking you to remember islands, I'm merely suggesting that instead of doing all the continents apart from one (and replace the last with only a sub-continent of it), do all the continents. Scrap Australasia and replace it with Oceania.
It wouldn't be fair if you took out Europe and replaced it with Scandinavia (a sub-continent of Europe), now would it?