Musically, Thrice Upon a Time is pretty much what you've come to expect from the Rebuild films: some tracks from the original TV series, some new songs to set the mood in key scenes, some repurposed classical music tracks, and a Hikaru Utada song or two to finish things off. Of course, just because it's a predictable collection, that doesn't mean you won't be humming “One More Kiss” for weeks to come.
On the visual side of things, Thrice Upon a Time presents some of the most fluid and dynamic 3D animation I've ever seen, though the transition between 2D and 3D is still noticeable. It also uses some live-action rotoscope to purposefully create an unsettling clash of animation styles, adding a bit of nightmare fuel to the film that will haunt viewers for years to come.