Thanks for the thorough feedback and I'm glad you liked the game overall.
As you said the barren rooms don't look good, by next DD I want to have at least one "proper" looking level, the system for adding custom environmental sprites and wall/floor textures in the editor is already in place, I just need to sit down and make them.
UI needs a rework too, I agree, and I'll look into those bugs as soon as I can, thanks again for reporting them.