Really cool! I wasn't expecting any songs in the jam to have vocals but it fits really nicely (both the Do Bahs and the Ooohs). I also really admire the amount of movement and how many times you were able to switch it up without it feeling at all jarring.
Also it fits the background music theme really well, because most of the time in Youtube videos they'll only have a song on for a few moments, so the song having a bunch of audibly distinct sections just means the song is multi-purpose. You could use one section for a big exciting moment and another for a slower more thoughtful part.
Overall really good! Harmonically very impressive, I can definitely hear that coveted minor 4 that we all love lol.
great stuff