Hi there. I'm happy to be here on this great site dedicated to Atari. Here are few "concepts" :) that I found some time ago, it was drawn by me some 12 or more years. I was planning something like this for PC and it was later scrapped because of the lack of programming skills on PC. So When I found these I decided I try to make it on A8. Basic, maybe TB ar AdvanBasic. It is a concept for and adventure "3d like" game.
Not sure how far your knowledge is about the Atari.
Seing the sketches in square, and the A8 screens side a side, you use the 2:1 mode? If you change to the 1:1 mode(*) in 160x120 resolution, you get more free resources, the aspect ratio is correct, and the CPU runs quite faster, resulting in up to 3 times faster screenhandling.
* GR. 7 with changes in the displaylist for showing 120 lines instead of 96 lines.
This would also allow enhancements for a full working game, just like digisounds during gameplay, a lots of colour enhancements, and so on...
im using gr.9. 80x192 currently. thats why there is the square so stretched in the editor (editor runs in 320x192 gr,8). I wasnt thinking about it to use such mode. But mode that you describe is software driven mode. gr7 has a res of 160x96. I'm not as much skilled to do it so, im using only turbo basic. Is it possible to change the number of lines from 96 to 120 also in TB Xl ?