First of all, let me say this is GREAT for your first try. I like how you incorporated all of them into the so fast, without any epic intros. It was quite small, however and I hope that number 2 isn't quite this length.
Maybe a bit more dialouge and humor. After link exited the building, without any dialouge you couldn't really understand what was happening. I mean, where'd Mario get the teleporter/time capsule/wierd machine? As for humor, for a longer show, it really helps keep things going.
A preloader could be nice.
For characters I want, I'd appreciate Sonic, Yoshi, Some Pokemon (not just People), StarFox and if you could...the dog from DUCK HUNT!
Also a Super Mario World BG would spice thing up a bit.
The premise for this is quite interesting. I once did a short RP called "Videogame Mashup" some years back and it resembled this quite a bit. I would love to see you expand on this a bit more.
The animation is quite nice, a bit pixelly at times though. The music is pleasant, not annoying. However the dialogue needs some beefing up. Make it funnier or something, really use your imagination with inside jokes or something. Otherwise we're just watching VG characters walking around doing stuff together for no apparent reason.
Maybe even invent a reason for all these characters coexisting, and give them a badguy they have to team up and fight. I'd really love to see you expand on this, bro.
Well, it's not bad per se.
I can understand how this could help you learn flash, since it's basically learning how to use movie clips and the like. But still, it's a sprite movie. Besides being extremely overrated concepts, it's not really YOUR work other than the arrangement of figures to create your story using premade graphics.
I invite you to create things that are fully yours to further learn more about flash.
I'm not sure I follow any sort of story though