Combo videos are actually quite irritating. The bad parts are the only parts I'm interesting if I'm critiquing.
Alright, first minute of the movie, totally useless. I don't even want to know why you picked a song about slowly cooking pasta.
Alright, so, right off the bat: You're a good player with near-perfect timing and spacing. HOWEVER. I am tempted to revoke that statement upon seeing you play better players.
The marth was pathetic. I don't recall him landing an attack once.
Most of the other players seem to have forgotten that they were playing after being hit by anything and just stood there. They need to learn what the R button does. I felt like I was watching you attack Sandbags.
Things to improve: Honeslty, you covered most of the bases. However, this is a combo video. I don't know what you need to improve because you can't critique a combo video.
Things you are apparently good with:
Spacing was perfect. If that Marth wasn't so dumb he might have considered spacing himself better. Since he's not, good job.
Your aerials connected almost all the time, and you know how to follow-up / set-up. Follow-ups/Set-ups are good things to have. Being in a combo video still means you know how to do it. As for the perfect timing, again, hard to tell.
With all that said, I have no idea how accurate all this is. Please post real matches. Even if you lose it doesn't matter, as long as you think you played like your usual self.