I like the design of the little flash thing, but the characters look a bit strange; the arms especially. The arms don’t really have a flow to them, and the hands seem a bit odd (just brush up on hands a bit, they’re pretty decent). You seem to have a tendency to make the forearm longer than the upper arm, just make some slight adjustments to fix that. The bigger problem I’d say is that they just don’t seem to have any dynamic. They’re kinda blobby. Try making them a bit “Swoosh”-ier. This picture illustrates my point a bit better: http://www.itchstudios.com/psg/tuts/tutlineart.jpg For stylized characters like you’re using, it pays to make things dynamic.

Also, you know how the bar around the bottom is outlined in white? Try outlining the buttons as well so they look like they’re part of the bar instead of floating above the bar.

In the background of the purple one, the silhouettes move a bit awkwardly. Given that they’re all one symbol, this is a bit typical. I just think that you could do a bit more to make their motion natural. Personally, I’d code something up involving sine and cosine waves in order to get a nice smooth natural movement, but I don’t think you’d be willing to bother with that.

In the opening, I think the stretch at the end is a bit too obvious, and doesn’t have the same snappiness that the rest does. I think that you might have been slightly off in the timing, but it’s too time consuming to check exactly. The plates might be better if they squashed a bit more during the initial move in than fitting it all in at the end, to carry the motion a bit better. Just a slight change.