Many people have already said it, but I haven't seen a Mario parody this legitimate in a long time.
The animation was smooth and consistent, and your attention to character detail was impressive. The scene which could've been improved were the first few shots of the Goombas talking. The choice of scene angle made it difficult to differentiate the two of them.
Script and humour was top notch. Scenes like Mario falling off the side of the stage, only to have 99 (now 98) lives were clever and kept me smiling the whole way through. At first I thought the scene with the two stoner Koopas were unoriginal, branching from an age old joke about the mushrooms, but the way you tied it in with the story at the end made up for it, as well as the witty dialogue. The pacing of the parody also impressed me, it never seemed to drag on.
Last, but not least: Voice acting was brilliant. Reminded me of the level of voice acting you'd expect from people like Egoraptor. I'm hoping to see more of SirUndead's voice more often.
Keep doing what you're doing, because it works. Very well.