12a Characters listed in play (6) -i-d-s Tildes? But they are signs not characters.
6d 15,something to do with a fast one, say (6) -u-l-t. Bullet? Why?
22d Get to taste bitter (6) --n-r-. Answer to this will give me 22a.
Pullet parses in a similar way to 21d if you have done that one. What do you do with fast one? You pull it. Makes more sense than bullet, which doesn't match the definition.
I see a lot of iffy clues on AB, but I thought those three were sound - 'in play' is perhaps a slightly questionable anagram indicator, but I've seen much, much worse!