While I'm unsure if you should add or edit in the description some *spoilers* since the movie gives something people who didn't finish Undertale wouldn't know (and would at the least be confused in at the end), the timing and framing of the song, lyrics and animations are very smooth and streamlined. The plot is easily followed given how you placed each setting and the ending leaves the moment of realization. . .that leaves a very good impression of what Undertale's message is.
Nice work with the 'vocals' by the way :) It was nice of you to give Frisk a voice matching the song!