indie game developer :)
While I am not sure about the fan factor, I'd say it looks pretty well modded. It's not a simple "add maps, textures, etc." mod.
I like how cursor changes shape and displays a hint!
Clever little game! Real treat for those who want to challenge their brain :)
Clean code, extendable, cross-platform, unified lighting, decent tools, easy to mod, Blender <> idTech 4 art workflow. Good ol' engine with a lot of potential.