i remade the first two rooms in undertale using this tool!
A Blender add-on for building tile based low-poly scenes with paint/map editor like tools · By
That's very neat! Undertale is in my to play pile, but with working on Sprytile on my free time, I don't know when I'll get around to playing it.
I notice in Sketchfab that you say it looks different in Blender. Have you tried using these settings for Sketchfab?