Not bad, I like your brick and tile textures, but you got some weird perspective going on there. There seems to be several different vanishing points.
If you have buildings with dimension you need to use the isometric diagonal lines that are 2x1 pixels, rather than what you have here, 45° 1x1 pixel. But if you
do use 45° lines, they should all be consistant ie. the roof and floor of a building would be parellel and the same length. Otherwise if you have a vanishing point (if you are new to art follow
this link for a definition) all lines that are not horizontal of vertical should point to that.
Sorry if my c&c is a bit rusty, I haven't done it in a long time.
Keep up the good work!