I've got one that I've never figured out. I've done so much research and tried out abandonware and was never able to find it.
It was a computer game from the early 90s. I played it on a demo computer in the electronics store Silo. I do not know if the computer was a PC, Mac, Tandy, OS/2 or whatever else. I do know these facts:
- medieval/fantasy adventure game style like King's Quest, Quest for Glory, etc
- had text input like Leisure Suit Larry or King's Quest IV, using commands like look, pickup, pet, etc
- had either a white horse or a unicorn in it
- it had color graphics
Not much to go on, but I haven't been able to find any text input games similar to the theme I remember. I do remember it being text input because I remember multiple times to figure out what word I needed to use to pet the unicorn/horse.