Bumping this thread, because I've been learning something as of late: you know how many of Don Bluth's later movies have been really lackluster and weak in comparison to his darker, grittier, and stronger earlier movies? As it turns out, there's actually a reason for that: studio interference. ROCK-A-DOODLE? THE PEBBLE AND THE PENGUIN? A TROLL IN CENTRAL PARK? All of them were deviated away from Bluth's original visions for each of those movies because the studios felt they were getting too dark and scary, and needed to be brighter and more light-hearted to be friendlier for kids.
Hmm, that was pretty much one of Bluth's main reasons for spinning off from Disney, because he felt they were going in that same direction, while he knew kids were able to handle more mature themes and storytelling.