Grea tiles! Although instead of using that black color, could you use a lighter black color? It's kind of an eye-sore when you use the blackest black you can use on graphics because most people use that color for transparency.
As for the shape of the house... The house looks TOO square man, is there any way that you could make it look less-like a box?
Ok, for the walls and roof of the house, it would be wise not to use that type of texturing on those. Try making rounded off tiles for the roof, and planks of wood for the sides of the house.
I hope I helped in one way or another
