Oval Office Tidy Up

Somebody had a very bad day at the office. The Oval Office, to be exact.

Classified files are everywhere. They're piled on the sofas, stuck under the desk and spilling across the carpet. More than a thousand of them, each one stamped with a country's flag. And somewhere under all that paper is the one thing nobody wants to lose: the nuclear button.
Your job is simple, at least on paper. Clean the place up.

HOW IT WORKS
Grab a file and take a look at the flag. Then walk it over to the shelves, where every shelf belongs to a continent: Europe, Asia, Africa, North America and South America. Put the file in an empty folder and that folder now belongs to that country. From then on, only that country's files go in there.
Put a file on the wrong continent and the shelf won't take it. Try to sneak a different country into a folder that's already claimed and you'll get the same answer. So you'll either know your flags, or you'll learn them pretty quickly.
At first you can only carry three files and every one of them just says "Secret File." Keep filing and things get easier. You'll be able to carry more at once, you'll move faster, and eventually you'll be able to read the country names right off the folders.

FEATURES
- Over a thousand classified files scattered around the Oval Office
- Flags from countries all over the world, sorted onto continent shelves
- Folders claim a country the moment you drop the first file in
- New skills as you go: carry more files, walk faster, reveal country names, spot the right folder from across the room
- A timer and a best time to beat
- No combat, no rush unless you want one. Just you, a messy room and a lot of paperwork
Some people will finish it in one sitting. Some will start by recognizing a few flags and leave knowing exactly where Benin is. Either way, the office will be spotless, and the button will finally be where it belongs.