Hi,
I took the time and resurrected an old challenge site, originally hosted at quiz.ngsec.com.
If you are interested in old school challenging, you can try it out at
ngsec.csokavar.hu. I had much fun while working through these levels back in the days. Today it has a different flavour, since some of the levels became harder to solve in modern linux environments. It has low overall complexity, but I'm curious if some of you find it entertaining.
Good luck!
encse