Now that’s what I came here for

This grid had four good, distinct categories, but the "Sorry" group wouldn't accept the category when spelled, as it normally is, with two words. That's just mean. I think a snugger match could have been found than "Mitty" but I won't complain because that was the one that helped me identify the category.

Got me - excellent grid

Yeah the “Sorry” group didn’t accept the answer as anything but a single word. Other than that quite a clever one this one

The Walter Mitty answer is actually slightly different from the other three in its group, so I think an answer that fits identically could have been better. Also, the 'Sorry' group should really accept a couple of other terms other than just the one word option. Clever grid, though! Interesting categories and a good one to puzzle over.

Very clever. 221B is quite a blast from the past for me!

Clever, I need more practice

Boardgames is the answer but it won't accept Board games?!