Nintendo hasn't messed with the tried and true formula of the original, rather they tweaked and polished it to create another huge hit.
Okay, first things first...I'm very upset that Kirby was not a playable character in the demo. I wait in line to play (which luckily was very short), get to the familiar character selection screen and...no Kirby! Aaaaghhh!
Sniff. Sorry, just had to get that out. After the initial disappointment wore off, I settled on the Yellow Electric Rat and jumped into a 2 CPU, 2 Human player frenzy on the F-Zero battle ground. While most of my focus was on the detailed characters and learning the new control style, I couldn't help but notice how much the level itself was a part of the fight. I died the most from the level, which has cars racing by and which actually moves your location along the track as the battle progresses. Woe is the character who is not on an elevated platform when this happens (Piikaaa Piiiikaaaa!).
Going back to the control style, it consists of a very simple layout like the first game. Unfortunately for me, there is now a Hit Button (A) and a Special Attack Button (B) which seems similar to the original set-up, but I had trouble executing Pikachu's moves. Either the moves changed (quite possible) or I just suck (also quite possible), but my little Pika pal got his tail kicked quite a bit, with only an occasional Thunderbolt to blow away an opponent. One other apparent change is that the R Button no longer grabs anyone. It's strictly a defensive move. Again, this could be because I didn't play enough, but it seems like this part of the game has been changed.
Despite my control troubles, the game played very smoothly, which sounds a bit contradictory, but I think the main problem was relearning the controls, not the controls themselves. The game felt very responsive and I'm sure once I get acclimated to the game, everything will be great. We'll know tomorrow.
The sound on the game is very similar to the original's. While it's hard to judge sound well at E3, SSBM didn't seem to be anything special in this department. Mind you, the sound effects are spot on for the game, but having been blown away from the audio on Rogue Leader (which is very nearby), SSBM is a bit underwhelming on the audio front.
That's about it for the first impressions. I should note that I played again using Samus and did a lot better. The cool thing is that she now has a missile attack...if only I knew exactly how I did it. Also, as far as the number of battle arenas, I don't know how many there will be, but there are more in the SSBM demo than in the original game and the screen looked like there could be many more hidden. Overall, the game so far seems every bit as fun as the original with great responsive controls. Now if only I could take it home and learn some cool moves...