An error in the Mega Drive/Genesis version's palette storage results in the game appearing darker than it actually should be.
The first stage of the Genesis version includes a number of continuity and historical errors. If the player does not catch up with Clara in time, she will say something and fall into the Ravine. Her grave stone will read that she died September 5, 1855. The date in the movie, however, was September 4, 1885. Two of the quotes that Clara says when she falls into the ravine ("I wish I was Mary Poppins." and "Geronimo!") are references to things that came out after the time the game takes place (the first Mary Poppins book came out in 1934 and the Geronimo yell was started in the 1940's).