GeoGuessr, as you might have guessr'd from the name, is a straightforward game.
You get dropped in the middle of a random location on Google Street View and have to guess, based on your surroundings, where the hell you are. The closer you are, the higher your score. Pretty simple right?
The difficulty varies wildly. Sometimes it'll drop you in front of a sign that reads "Welcome to Rio De Janeiro", and other times it'll strand your arse on a dirt road that could be almost anywhere. One thing is clear though: It's stupidly addictive, and perfectly simulates the sensation of waking up in the middle of an unfamiliar, foreign country after a week long bender.
I...I can't stop playing it, you guys. Play it here, if you dare.