To operate a pachinko machine, a player buys a quantity of steel balls (like ball-bearings) instead of tokens. The payoff to a lucky gambler--which is also in steel balls--is then exchanged for gifts or cash. A big payoff results in thousands of balls in your tray.
I reflected that accidently dropping a big jackpot would cover the floor with ball-bearings. Any customers who stood up, would probably be slipping and falling in droves! I didn't see anything like that occur. But the concept seems hilarious, and might make a funny scene in a slapstick comic movie.