this could be SO freaking cool
things that need improving:
-voicovers. either get some people to voiceact, or don't do anything at all. having mario and luigi say echothers names and nothing else is kind of weird.
-sprites. links sprite is always looking over his sholder when facing forward. just shift his pupils to the center of his eyes. other sprites are cool, but i think kit would help if you could get them to face other directions, but i understand that that is really dificult.
-music. just put the bgm to some old nintendo game in the background, would do wonders for the movie
overall i liked it. if your stuck for ideas, why not make the source of the evil microsoft and the x-box/sony and the ps2?