Good grid with nice crossovers, and for a while I was convinced that "red things" was a group, so if that was a deliberate red herring (get it? lol) then very well played. I have one minor complaint/suggestion - try not to include plural forms in your linking terms, as I dropped from 10/10 to 7/10 this way. Doesn't really bother me, but it might grate on some people when they don't get the score that they earned. Cheers.

I was also convinced that "words that can have the letter S prepended to make new words" was a group. Lots of distractors!

Does not accept "bomb" for "bombS", total trash.

mad as a bat? nope blind as a bat

Hare, hatter, car, nail, hot can all be preceded by S. Don't know if that was intentional but I wasted half my time on it!

Good grid