Nice going for a first
I'd have to admit with the other reviewers, though I like the idea.
Story:
First off, you're presenting Santa as a thief. Here is a tip; if you're presenting a character with such a personality, you should probably start off with Santa actually stealing something, otherwise you could call him a murderer, child-molester, hippo and so on, without it having any meaning for the character at all. Secondly, you say three tests... Well then, what's the third? It gives a sorta dull feeling if you say you have three tests, but only uses two (closing walls and acid 'n' round saw). If Santa was supposed to fail in the tests, making him fail in the third would just put more meat on the story. Finally there is the ending, you are building up lots of excitement, and people will think "Oh what will santa do without arms and legs?" Having him killing himself there is like putting a big, fat needle into the balloon that was the excitement, which is quite lame. If santa WERE to die from that, it would be much better for the story and ending if he died slowly, possibly of blood lacking. I completely agree with Redmoron, on his point #3; Santa is a character known to climb up and down chimneys with ease and speed... And Jigsaw does say that santa can choose for himself... Using any other character (who could NOT climb back up) would make that better.
Animation:
For a first timer, this is really good, movement is somewhat smooth and the backgrounds, though a little cheap-looking, works nicely. It is slightly edgy, and shaky at times, Santa's face could do with a little more emotions (pain, horror, the likes). Also when santa's climbing down from his sled, the rope looks more like a pole than a rope.
Sounds & voices:
The sounds fit nicely into every scene, though I could use a little more sound on the round-saw, heck that thing is not designed to be silent. Adding the music to the climbing scene is quite nice to make it more exciting. Voice acting however is not good, Jigsaw is waaay too low and Santa seems to only be able to talk in one tone, no matter if he's yelling at the raindeers, being surprised and horrorfied by the first room or being cut to a pulb by the saw, you need to make his tone of voice fit the scene better. I like that you didn't voiced the elf yourself though.
Placement:
I think the Crew have made a mistake by putting this on the front page, no offence to you. As a first timer, this is great and should go in the 2010 christmas collection, but it's just not good enough for front page, sorry.
Hope you can use all this in the future.