I did this one a couple of months back. It started with a simple idea of an object transforming through out the video.
You can see the result here:
https://www.youtube.com/watch?v=xDY2P4K1Aw0

All the animations and backgrounds are made in Krita and later edited in a video editing program. I know the quality of the artwork isn't as exquisite as other projects you see being posted here but if you're into smaller animations this might help you acquire some do or dont's.

If you ever want to put something similar together theres a few things I learned from this I can mention. It helpes being well prepared and have a plan when starting. It sounds like a no-brainer but I started this project thinking: "I'm just going to do random transformations, how hard can it be?". But when you're sitting there, pen in hand, it's not that easy coming up with 50+ random objects and how they are going to transform into one and other. And to do it in a way that won't take forever.

You should also have a better plan than me when it comes to colors. As you can see in the video it's not everything that looks that clear or tasteful. I've also been having issues when it comes to gradients in the video-format. Gradients look great in Krita or when you save them as an image-file. But when rendering them to a video, especially when you fade between gradients or when they are in movement, they tend to look not so great. If you have any good solution to this problem and feel like sharing that would make me happy.

If you're wondering about anything just let me know.

I watched it and enjoyed it through and through! I love how the simplistic, but still very well drawn designs merge into each other, it's purely mesmerizing. It just has one downside, as it takes your attention away from the song

Thank you thank you! Very kind of you.
The song is available on spotify too if you want to listen on the music without distractions