Yeah, the engine is incomplete and improvements could definitely be made on what exists. But try avoid opening any of the files in Notepad. As you witnessed, it expects carriage returns in conjunction with newlines, try Notepad++.
As for the .obj files in this context, these are actually 3d model files for creating the tileset (one of the .obj files being the cosmetics and other the mask). This is a standard format so if you have any 3d modeling software (such as Blender) you can import it.
Has anyone tried to compile and run it? If so, I'm curious how it went.