I like these--especially the boar/portrait emerging from the background.

The main thing that bugs me is the contrast on all these, but I think it is more the palette to blame than anything.
The outlines, on the mini-mockups feel messy

if I were you, I'd get rid of the 'corners' or w/e on the outlines--but that's just me; the blocky boarders, coupled with the fact that they aren't black, but the next closest thing, do give them a very nes-y feel.

As for the emotes...They really stand out, which is a plus, but the shading seems almost too partial and subtle...again, it's a contrast thing--if it were mine, I'd go all out, maybe even hue-shift to give some more depth to the 'zz' and the music note. And, the outline on the sun; it seems overboard and is making it look messy...not sure how you'd go about fixing it though...maybe move the rays in closer?
My favorite one's the heart by the way

.
Oh, the spread apart guy...probably the best doodle in terms of value goes.
But yeah, shame you didn't get a mock up in...didn't seem like anybody really got one in

--well compared to the gameboy one that is.
EDIT:
Yeah, ignore the whole contrast thing...I've got some issues with my screen at home. I'm at school right now; they look awesome and the contrast is just fine
