I'm looking forward to seeing the characters and more of your game! The style and walk animation of the ones that I've seen are great.
I am working on one additional improvement to the Voxel Editor for the next release (which will hopefully be this weekend still). I took the time to look further into a "MultiMesh" object that Godot Engine supports, which does low-level mesh instancing and therefore allows a much larger number of instances (in this case, the voxel cubes). There was originally an issue with being able to set the color of an individual instance, but I think I have worked around it.
If I can get it working, there should be a good performance increase, especially on larger models like your doors. And it should help with the issue of the render limit where voxels start disappearing after a certain point, since each MultiMesh is only considered one render element.
Here is a colorful mess of 25,000 voxels that was part of my testing. :)
