Frozen.
The weak plot quickly became an overly predictable mess of Tangled and The Princess and the Frog thrown in a blender.
The setup was brilliant, but the execution sucked. Much like Up and disc 1 of SDoIT, the first act was perfect but it quickly went downhill from there.
Too many of Olaf's antics are just annoying throwaway gags for comic relief, like Eddie Murphy's lines in The Haunted Mansion, or Mike Portnoy's lines in BC&SL.
And that damn song. I've heard it so much that I never want to hear it again. Now I know why my dad despises Pull Me Under.
For what it is, it's great. It was just so overhyped that when I watched it, and got excited once the plot was established, I quickly grew bored.