The Walt Disney Company left so many unanswered questions in the 2002 visual spectacular, Treasure Planet. The story of a boy on a mission to find the lost planet and save his mother's inn. 

They left open questions such as who Jim's father was and why he left Jim's life, how did Silver end up a cyborg, and what was his fate after the events of the first movie. There are even fan made characters and theories about Jim's potential love life. There is so much potential for a sequel, and it's something fans have been waiting for, and would pay good money to see.