This game is so much fun: Peekaboom!
You are paired up with a random other player. For each round, one of you is a “peeker” and the other is “booming”. The boomer has a photograph in front of them and a word that associates with it (e.g. “balls”, “men”, “cooking”, “elephant”). They can click on parts of the picture to expose them to the peeker. The peeker has to guess what the thing depicted is. If the peeker gets it right, both players get points. The less of the picture was exposed, the more points the two get.
As the peeker makes guesses, the boomer can rate them as “hot” or “cold”, giving feedback to the peeker. The boomer can also pass limited clues in the form of “noun”, “related noun”, “verb”, etc. to the peeker. The players are against the clock to score as many points as possible before time runs out.
The really clever thing about this fun little online game is that it is being used as artificial intelligence research to teach computer algorithms how to spot the “important” parts of a picture: the bits that can be used to determine what the picture is of.
Give it a go, and contribute towards some AI research while you’re at it…