matches

[orange]

why the hell this isn't a solution:

[Vincent]

I wonder if the whole thing counts as a square?  I know it says no square of any size, but...

If not, leave the outside walls alone.

[countzero]

yes, the whole thing is also a 4x4 square, but orange has already broken that. I think this must be a solution. there's probably a bug in their solution checking algorithm. Or they thought they knew all the answers and entered them by hand (if they did this, it's very possible to forget a different form of a solution )

[Vincent]

Do the other puzzles say congrats or anything?

I've tried this one several different ways and there's nothing to say you've done it.

[countzero]

yes, they do say "good job, try the next one."