Nice! I'd recommend using Z as jump and either A or X as run to make things easier, but whichever controls work best for you are fine. I noticed some things that you could've done to improve your run, though.
Way Cool: Why didn't you just fly through the whole level with the cape? That would've been much faster, plus, you wouldn't have even landed on another platform besides the first one.
Funky: At around 8:51, couldn't you have jumped onto the ? Block and then jumped on the Note Blocks after gaining considerable speed? I'm pretty sure you could've made it.
Regardless, I think this is a great video!