Aw, so close.
Comedy is tricky. If even one element is off, it can tank the whole sketch.
The animation was fluid. The sprite art direction was genre-perfect, especially the food and food cart. The voice acting was spot on.
But what killed the skit (no pun intended) was how Luigi dealt with every thing. Luigi going bonkers? That can be funny. But whipping out a shotgun? On a site where random blood-n-guns as humor has been done to death? It just doesn't match up, and that lost a lost of humor for me. Violence isn't funny just because it's there-- there has to be a point for it to be funny. Or the violence has to fit the milieu of what you're using.
I mean, you're taking music, animation and overall cues in presentation from the Mario series-- which is fine! But then you're using humor that doesn't fit. I mean, Luigi going nuts and then sending fireballs after Mario could work. Or maybe smacking a toad into the horizon ala Smash Bros. The Mario series has traditionally been one of slap-stick, and if you use something that's too far out of place, the humor is lost, and then it can just look like you're trading on nostalgia ("Look! Beloved characters! Retro graphics!") instead of building on what you chose to make it funny.
I still think you're talented, and I hope to see more from you, dude!