Well, you can't just make mode7, because mode7 is one of the SNES's graphical modes, NOT a style
Also, mode7 isn't as useful as you might think, because it's only 1 flat plane.
Well It's not going to be too complicated, the map dosen't have to be extremely big, but it does have to have some size to it, and (if possible) walls. if not then I'll probably use sprites as the walls. And I'll probably use sprites for things like rocks, trees, and stuff like that. I hope that isn't too much, and if it is let me know and we can figure something out. Sound good to you?
And if it's possible I want to try and add depth to the map, things like hills and and holes, but again if it's too much then we'll go with a flat map.
I looked around and found a 3D engine by Trinitro21, here's the key: 43KNQEA6
If you use it make sure you give credit to him!
I don't think it would be very good for big maps, but it has a 3D object renderer, a SNES mode7 single textured plane renderer and even a 4D renderer.
I will look around some more to see if there is a better one for big maps.