Generated files were far above accepted, two things were noted:

 - Saving generated resource with ".tres" extension was the wrong move, now saving resources as ".res" files, since they are binary file sizes are significantly smaller and loading times are faster.

 - One of the reasons for the generated resource file is that images are embedded on it. Feel free to discard spritesheets or use it your own way, but they are unecessary for use on Godot Engine.

:)