Here are some game demos I wrote in 68k assembly. These are all for the Sega Genesis but maybe I'll add support for other 68k consoles.
Retail Clerk '89
Retail Clerk '89 started as a personal exercise to learn Sega Genesis programming. It's now a complete, albeit short, game demo. Although originally inspired by Phantasy Star II and III it morphed into more of an interactive fiction / casual adventure game. It's not especially fun but has a complete story.
Retail Clerk '90
This is a sequel to Retail Clerk '89. Since it's possible nobody played that, Retail Clerk '90 is a mostly independent story. Playing the first game wouldn't hurt though. I guess it might hurt a little if you don't enjoy it.
This is a demo specifically designed for speedrunning. Speedrun Tower is set in a building with a confusing elevator system. Your goal is to reach the top floor in the fewest steps possible. Unless of course your goal is to visit every floor or view every event in the fewest steps possible. This demo was also an excuse to try different approaches for achieving pseudorandomness on the Sega Genesis.