80's or 90's animated movie?
So I've been trying to find out what this movie is for like 7 years.
All I remember is that the animation was along the lines of The Pagemaster, and it was about a boy who wakes and is taken away on a bed by an old man over the ocean to castle, where he is then asked to hold a key by the king, and it is his responsibility to not open ONE door out of all the doors but he does, and this black sludge comes out and tries to overthrow the castle and takes the king away, so the boy has to save the king by going through a forest.
If anyone could tell me I would love to know, it's been driving me nuts, I was born in 91' if that helps, and I was like 5.
