So, seeing as there have been more than a few nepbar clones since the original, I assume it was based on some kind of like, asset pack wasnt it? not that it would be terribly difficult to manually replicate the general structure of the main area.

at the very least, I know some of the assets seemed like an asset pack, since Ive seen them in other maps.
[spoiler]anyone know which was what? :)[/spoiler]