Yep, I really love retro games (as you may have noticed), so I'll probably be pretty active in this section..
I still remember (and actually play from time to time) one of the first games I ever tried on my first PC (a green/mono 4,77Mhz IBM 8088), and it was actually one of the only games I could play on that PC since it didn't have a graphics display, the green/mono monitor could only display ASCII characters...
But Castle Adventure worked perfectly on it:
http://www.thealmightyguru.com/Revie...ure/index.html
The game wasn't like the (really) old school text adventures that were common at that time, but it used ASCII characters to simulate "graphics" like the castle, rooms, monsters etc.
"Screenshots" here:
http://www.thealmightyguru.com/Revie...A-Screens.html
You can download it at the bottom of this page, but beware; it's a whooping 43Kb..
http://www.thealmightyguru.com/Revie...A-TheGame.html