I put this together in the last few days. It is based on and builds on RevEng's adventurer sample. You can walk around 255 different screens on the map, and there are currently only 15 unique screen definitions. There is nothing to do in this demo but walk around.
There is also no collision detection so you can walk through walls. If you stay with the openings the screens do connect properly. I don't know how to do collision detection with the background and haven't tried yet. I'm also sure there is a way to use the screenmap command in the main loop to change background colors during the game, right now I can only have three colors for the background. Since I haven't figured out how to change it during the game, I'm including two samples. The "green" sample shows what the first screen would look like with that color, it makes the rock sprites look like trees. The code "adventurer4.bas" is the brown version.
You may be able to guess what game I based the sprites & background on.