I love this tile set! But pixels or something seems off. I've combined your outdoor/houses section with my preferred floor/ground set, but for some reason, your tiles appear to be a pixel or so off, because there's a number of tiles that see to grab a pixel or two of the tile right next to it.
This tile set on it's own doesn't do that. All I did was copy and paste to another tile set in Gimp, saved, and, exported. It's probably something on my end causing it. I'm till new to this making games/using tilesets.