Mail Sort — free browser game

You are running a mail distribution center: parcels drop one by one from the conveyor, and each one is labelled with the three-letter code of its destination city (IST, ANK, IZM, BUR, ADA). Your task is to route each parcel into the correct mail slot before it hits the ground. You can select the five slots at the bottom of the screen with the 1-5 keys, or tap and click directly on them; the Space key starts the game, and the R key restarts it. Every hit into the correct slot increases your score by one and gradually raises the falling speed of the parcels; a wrong slot or a missed parcel counts as a mistake, and three mistakes close the postal day. Here is the catch: after every 8 correct sortings, two slots swap their city assignments, so you cannot blindly trust the sequence you have memorized — before pressing a shortcut key, always take one more look at the current city code above the slots and try to stay calm as the tempo speeds up.