Most of Russia is in Asia. The European part of Russia (about 4 million sq km) is still the biggest "country" in Europe, but the Asian part of Russia, about 13 million sq km, is the largest "country" in Asia as well, ahead of China which has about 9 million sq km.
Forcing us to only put them in order takes away a lot of the fun. It took me half the time to figure out why "USA" didn't work (had to type out the whole thing), then the other half to figure out why it wouldn't accept China or India. Either let us type all the answers without having to put them in the yellow box, or title it, "Largest countries by continent, In order of geographical area.
The point is exactly for you to take more than 1minute to make the quiz. Just typing random country names is very boring (but if you like it, there are thousands of quiz for you on JetPunk!).
100%. Easier than the most populous countries one IMO, maybe because we're more used to seeing representations of countries' sizes on a map than we are used to staring at population figures.
And by the way, USA works.