I'd love to see a darker japanese castle tileset. I plan to have a ninja clan in my game, and that'd be awesome to use with this.
I think that has been requested but I'll double-check the list and make sure.
If this didn't happen, I can help show you how to make it look darker with overlays, parallax, and good lighting. If you show me your map, I can screenshot it and do a quick example/help you with it
