In order to properly integrate the tileset into your game, you have to set the passability yourself.
This is just the graphic. If you would like, I can create a list that describes the correct passability for each extra tile I have added.
**Basically, just copy the PostTown-Interior and paste it into a blank spot, and change the graphics for the copy to the tileset on the main page. Then, set each of the new tile's passabilities.