Ha! In pre-Covid days, folks would bring jigsaw puzzles to the office and leave them in the break room. This is a company of around 300 bodies. The idea was that someone would open one and start it, leaving it on one of the tables. During the day, other folks would wander by and add to the puzzle, until it was built. Part of the idea was that you may be working on that puzzle with someone who you hardly know, from a department that you have little day-to-day relations with.
Then, some diabolical person left a puzzle with all identical pieces, except for the outer sides/corners. I think it was a picture of Butchart Gardens or some other similar thing with flowers and trees and water. We finally finished it, but I think it took about two months.