If you visit the Google homepage right now, its doodle is a little different from normal. Instead of an homage to some great member of human history it's an actual, fully playable multiplayer game with a Halloween theme. It's called The Great Ghoul Duel and it sees you and your three teammates attempt to capture flames from within a haunted house while the ghosts on the opposite team do the same.
You can get power-ups and boosts from your friends, steal flames from enemies as they're about to cash them in, speed up, slow down, find hidden passages around the map, and ultimately try and collect the most to win the game.
What makes this game surprisingly fun, though, is the theft mechanic. While you can go around and collect the little flame spirits yourself, you can also steal them from the other team. To do so, you need to bump into the trail of flames that follows around each player. Doing so steals the ones you touch, which can, in turn, be stolen back and leads to frantic spinning matches as you both attempt to take what was yours from the other player before racing off to deposit them in your team's goal zone.
Teams get stronger over time, giving them abilities like invisibility, magnetism, and increased field of view, among others. That makes the game more frantic as it progresses and adds new depths as you near the end of the round.
It's not perfect, as half the time the teams aren't full or some players are AFK, but it doesn't matter. It's a fun little time waster for a few minutes throughout your day.