If you look at Diddy and Dixie, you see that their hair/tails/whatever is blowing upward, making it look like wind resistance. DK's arm, on the other hand, is going downward. For the full effect, I think you should change that arm.
Almost everything I was going to say has been addressed. Can't wait to see Diddy's heavy animation in use. Oh, are you using the correct partner palette? They seem incredibly dark, as if you're using a cave palette or something.
I saw the two videos on Youtube! Great work! You're really getting them done fast! Did you happen to notice if Clapper is missing any frames? I did those sprites a LONG time ago, so it's very possible.
With the exception of Kiddy, all the sprites that you used for the "looking straight ahead" frame doesn't really match with the rest of the sprites in the animation and makes it look really jumpy. :/
Squitter is looking great! If I can tell from the video, the minor adjustments seem to be his idle speed, and the "wobble" in the web platforms. Fantastic job, guys!
http://img718.imageshack.us/img718/231/signsz.png Some editing I've been messing with. The Expresso barrel looks pretty decent and the Winky sign icon looks ok. I'm trying to get the Winky icon to look good, but it's not working out. I just think he'd look good in an overhead view like Squitter. An...