The following two videos are visually identical, and both use the same performances of dialogue.
In the first version, I emphasized the dark side of the story. The music (composed by me) is meant to be unsettling, and the piano is layered with an unearthly "dolphin" voice, hinting at the supernatural aspect of the story. I added extra wind to make the woods seem colder and more desolate, and when the protagonist stops to listen for the troll's voice, I added a distant dog bark for menace. The troll's voice is closer to a person's natural voice, and as his freedom approaches, his digitally heightened voice is layered with its original much deeper pitch to indicate that he is much more powerful than he appears to be. As the girl unties the troll's string, the piano falls out of tune, leading up to the moment when the troll is released, accompanied by copious thunder, synth accents, and more "dolphin" noises.
In the second version, I took a lighter approach, making the forest less threatening with singing birds and a piece from Tchaikovsky's Sleeping Beauty. I also present the troll as more of a sympathetic character, primarily through his voice, more chipmunky and wholesome, with none of the ominous layering of the other version. I wanted to make the girl less appealing and more of an intruder in the troll's forest, so I accompanied her first appearance with two simultaneous raucous rock songs (for maximum clashing)—sharply contrasting with the fairytale serenity of the Tchaikovsky piece. When she stops to listen, I added bass-reduction for a more diagetic speaker sound, as if she has an aura of abrasive music. The song doesn't stop until the troll is drawing her in, when a twinkly orchestral Alexandre Desplat piece replaces it. The moment when the troll possesses the girl is much less dark than it is in Version 1, in keeping with the more troll-sympathetic approach. It is mainly achieved through another Sleeping Beauty piece with copious echo and reverb, layered with the troll's squeaky voice and the digitally sped-up voice of the girl. At the end, the original Tchaikovsky piece returns, signifying that all is well in the forest.