That's a tough problem, here is my idea I hope it helps. It combines both Deep Inside and the original title which I like very much.
"A Wish Deep Inside the Dark"
Or You could play with the font a little by either bolding and/ or capitalizing "Deep Inside" like "A Wish DEEP INSIDE the Dark." You could change the font for "Deep Inside" as well to highlight it and let people know it's still the game they love and know.