One of the most popular games at the local arcade bar is a classic game called Tapper. The arcade bar has basically all of the top arcade hits, a few SNES/NES booths, but Tapper seems to consistently get a good amount of attention.
The gameplay is really simple. You move your bar tender up and down between the 4 "beer serving" stations and serve beers to customers. To "serve a beer", you pull a lever down quickly and release it. The trick is the customers come in waves, and you have to serve every customer, and/or catch returning glasses that come back.
I'd recommend using similar gameplay, but adapt it to loading washing machines and serving customers with laundry. The gameplay is super simple (anybody can play it). The game design is also simple (it's single-screen gameplay, there's only 4 positions the player can be at).
Many versions were made for different systems. You might play this version here: https://archive.org/details/arcade_rbtapper