I for one think its really cool, and humorous, especially the animations, they are particularly well done.

(not to go against what FRAWG has said just my opinion)
critique:
First thing i noticed is the cave that the "enemies" enter the stage from is rather fake looking and doesnt fit welll with the rest of scene which is rather good. It reminds me of solid jelly that you heat with boiling water, place in a mold the leave in the fridge to set. If it were me, id scrap that part and try again.
When the character (with the sword) is at the last few frames of animation and opens his hand that is not holding the sword, the thumb looks out of place and detached, because of the outline that runs around the thumb and through the hand.. its also rotated toward to ground a little too far, positioning my hand in the same way that was intended i can see that i can get a little over a 90 degree angle between my thumb and index finger and thats only when i dont position my hand flat out.
Finally, there seems to be borderline pillow shading going on in various places, most notably the chest plate, but that might be how it is ment to be I dont know.. considering the main light source is behind the character, you could try doing some back lighting on the various pieces of plate that are missing it (the boots isnt one of them). Since this is supposed to be a Super Nintendo concept where the characters lighting should fit in various lighting conditions you may not want to do that though..
Meh.. Thats all I had to say.. Hope it helped