WOW I really love the graphical style of your game, very nostalgic
You're welcome, well done on making the game it looks awesome!
It's definitely possible to create some kind of rectangular map from them, but to be honest, I don't know what projection that would be. Currently the shader works by starting with a flat texture, and then applying a kind of 'spheriphication' filter on it. So if you just don't do that you would have a map