What it teaches
The capitals of the countries the other world games already use, so the same eighty countries keep coming back with a different fact attached each time.
Capitals are pure paired-associate learning — there is nothing to work out, only something to know — which makes them the perfect thing to put on a spaced schedule.
What to look for
The wrong answers are other real capitals, which is what makes the game work: a child cannot pick the only city-sounding name, because they all are.