(site author) Thats great feedback! Honestly, I've spent the last several years trying to learn how to train models that generate reasonable sounding music but am still trying to figure out what it is that i'm building and how to present it.
In this case the product is very technical -- I have to open and operate sophisticated MIDI software. Presenting it like a phone app is confusing. Even more so, it looks like an MP3 player because it just presents a few icons and these have nothing to do with how I would use it. The video tutorial is great, but video is linear. It needs some text support. Particularly because it starts up with nothing but a desktop. Consider adding a title so it is clear that it is a video not just a picture of a fish.
In sum, it's a technical product for technical users. The presentation can be dull because the presentation does not have to fit on a page in the iOS app store. At least not yet.
Speak to current (or, if you don't have them yet, prospective) users. In real life. That way you can construct a landing page that speaks to them.