Wayyy too big!
Well, the music was high quality and stuff but for a sprite movie that barely lasted 3 minutes, the filzesize is just way too big. For people on a slow connection, its gonna suck if they have to wait so long just to see a VERY short series of mario skits. Maybe you should take the song out of the preloader to cut it down.
As for the flash itself, it was kinda boring lol. everything moved really slowly and to be honest we've all seen mario fall off a cliff/get hit by a random object/ swear at luigi 4,000 times already!
so yeah, if you make a fourth episode, I'd increase the speed and perhaps add some punchlines that weren't predictable. as well as cut the file size down (compress your sound, etc), this should honestly only be 1MB tops.
hope this helps