Technically, there is going to be a sequel to Curse at Twilight. But Amanda is very busy with Pixel Pygmies and then there will be the next Aveyond game coming up so... I don't know when there will be a next game.
Far as I can tell? It was planned, but nothing has been said since CAT's release. Just like how Gypsy's Tale never got a sequel even though the ending implies that there will be a continuation, there is a chance that CAT won't get a sequel either.