No, it's approachable, I tried myself again and got to 7:55. (of course with the use of your video, because, I mean you are part of the developing team, developer myself here and I laugh when people take time for my puzzles when I know the answer myself lol).
But., I mean, honestly, no offense, but the games speed run, I think any games speed run is just not wise or not my style. Especially, this having a musical approach, it creates more freedom to create something. Personally, platforming is easy, but making a tune with the given song, it's more relaxing. I would not worry thou, not gonna try to anything again and probably my score is not that high, I guess looking at your video you can easily do that in 8 minutes. (again, with given approach to the jumping and that step when you open the 9/9 door).
For you and the rest of the developing team, I would recommend and of course encourage to put more emphasis on music, it's neat and creating notes is more important. Well, that's my opinion I guess.
Thanks for making the game and good luck on your future projects.