I think it's really cute how they handled the case if the user unchecks all of either the "Type" or "Difficulty" filters hehe
I get a lot of “yeah but what if they do something like search for things that don’t exist” (or similar situations) and some weird ideas follow about how they user gets confused and the software is supposed to solve all “user behaves illogically” problems and we get some really strange solutions that makes the software even more unpredictable.
Like no man, search for nothing is “yo you goofed and searched for nothing”.
/rant