This is the final release (maybe) of what I called Zeuropa (below). 13 levels, some the same as in Zeuropa, some different... The author says these are all the ones that are semi-decent and don't crash. I'd agree that they're pretty good. Still no docs.
14 levels. On the whole, these are really nicely done. Many are variations on a theme (one map will be a vacuum level, another the same level with oxygen). There are a few bugs, but no fatal ones, and the general quality level is quite high. No docs.