For me, completing the Spiral Matrix, I did not find the hint for the third and final section relate-able at all to my solution.

Essentially, it assumes a bit too much the shape of the resulting solution.

That's not to say I didn't get value from the hint, or that I think others will not - on the contrary, it is a valuable and clear hint.

The unfortunate part is just the feeling of being taken completely "out of it" in solving the solution with a slightly different approach and wondering momentarily if somehow one is wrong, even though one is passing all the tests.

The recap is also fairly lacking in content, but I imagine that is clear to you already.

Nice job on the site, generally. I only had a couple hiccups with submissions and some weird aliasing on the editor if I would edit a line before it redrew.

Edit: add some dropped words