How are these tiles split? Most programs will not accept tilesets that are not uniformly spaced.
Viewing post in Retro Tile Set #4 - Under the City - Free comments
At the moment, they're organized against a 16x16 grid, with tiles that fit in 16x16 positioned that way, but the sprite sheet at the moment isn't designed for quick importing, but for manual extraction. Once I've done a few edits, such as doing a few more tiles used for bridging other tiles, I'm going to organize them better and can provide smaller sheets with the various sub-sets of connecting tiles that will be easier to import into programs.