Damn good.
Heh. What a funny and original point. Those poor poor sprites, all blocky and pixelated in this land of vectored smoothness. =(
I only have 2 suggestions. If you do indeed make a movie in this style again, change the text bubbles to a more cartoony style...white, or another solid color with a same-colored tail/arrow thing. The gradient bubbles clashed both with the text and the style of the rest of the animation. Also, see if you can't put just a touch more work into your editing. Mario's sprite had a rather hefty white outline around it in places, which should be easy to get rid of if you zoom in, since he has all square edges. When the new character walks on screen, the stretchy effect you used to show him walking across the background looked really odd, and not all that good. If you can't get a wider swatch of background to scroll under your moving characters, you can always copy and mirror the background you have and then paste it next to it's mirror. The edges will line up perfectly, and while it may look a little weird, it will look better to scroll that than stretch a too-small background oddly.
Your choice of music was fantastic, especially the techo you used on your production splash screen. I got that song off of mp3.com back in freshman year of college, and it still kicks ass. All around it's a really good movie, and it's going into my favorites. I look forward to seeing some more of your work.