Hi, I liked your set of tiles, I was in a creative mood and decided to develop your idea.
I'm not a professional but I like to do graphics sometimes. I upscaled your tiles (now 32x32), extracted a palette from them, added my tiles to the existing ones (I did not modify yours). The ground tiles are ready to use, and the new castle wall tiles are also ready (but I want to review them). Now I don't know what to do with them :-). I am attaching a file for review.