I think one last thing that could be added to this is lights, in the style of what can be done with top secret 3. It would go well with the style I think, and would be easy to draw (just have a solid white tile, and 8 angled white tiles). Hardest part would be making the actual light source tile. I think the tileset is still a little bit lacking in eyecandy, but having something like this would be simple and allow for some rather interesting visual designs.