So this is going to be niche in that you're probably going to be pretty lost without some programming knowledge (javascript knowledge is better but probably not necessary), but Untrusted is a neat game that seems kinda like a low fi browser take on doublefines hack n slash, except (from what I've seen of HnS) it's even more explicitly an exercise in programming.
Some levels are pretty constrained in what you can do, but others allow for quite a bit of latitude/creativity in terms of solutions. Also "walkthroughs" such as they are can be found by searching for "foo.js" (found at the top of the code panel) on GitHub Gist
For example, the first level (which is trivial anyways).