Hi, I just finished creating the first iteration of ReversingHero challenge.
It can be found here: https://www.reversinghero.com
ReversingHero a reverse engineering self learning kit (x86_64) wrapped inside one binary file. It is made of about 15 levels, with difficulty gradually increasing. There are no specific rules for solving the levels: everything is allowed.
There is also a set of videos containing hints and solutions for every level. The videos are currently being edited. Until they are ready, you can start taking a look at the binary (: