Wonderful improvement. While I don't think the old one was that bad, it definitely doesn't have the solidness that this version has.
I love what you did with the color first of all. Your previous version had a very dull look to it, while this one seems to jump off of the page. Bold colors and strong lines keep all the objects from blending in together, as they did in the older version. I think this version is more true to the typical isometric style all around.
Again, the older one isn't bad by any standards. It's more of a textured piece, while this one is much more bold, a style I certainly prefer when it comes to pixel art. Nice update nonetheless.