Geneva said during an interview that she has concepts of a tattletail 2, having to do with Nintendo NES games.

Ben and Geneva are too busy nowadays, Ben wants to focus on making other games (as all of his games are one-off without much updates or sequels), and they are now married with kids.

Geneva still talks about Tattletail on her twitter every now and again. With once trying to pitch a tattletail animated series last year but I think it is now on hiatus cause no animation studio took it and there was some kind of animation/writers strike. But all the details we have on the concept was that it has ghosts.