Alright, reverse order:
Pako: I love the style you have, and I think that's actually very good (and the first thing resembling a human I've seen of yours :P). I like the fact that he killed one of those damn gnomes. I hate them.
Depredation: Very clean looking design, but I don't like the fact that in the full image, it's just in the corner and the rest is blank (I like pictures that have lots going on :P).
Mogly: Different approuch to an explosion, and it looks good. What I don't like is that at one point near the end, when it goes mostly smoke, it looks weird, and too wavy. Also, like you said, it's a big filesize for just that.
Penboy: Interesting, but I can't quite tell: Would the white part be the canyon part, and the rest be rockage? Or vice versa? Or is it just a design and has nothing to do with the actual 'canyon' as it were?
chillyphilly: I love the shading on the cape. It looks very nice. My one problem with it is that it seems that the guys torso is a bit too short (or perhaps his pants are just high) and that it sucks in a bit too much in the middle. Otherwise, very nice.
Radioactive24: Looks alright. It looks like a Gameboy advance, at least :P If I wanted to be really picky, I could say the left trigger button on top is a bit too rounded, but that's being very picky.
23450: I like the detail along the wall (the snow). I also like the shading and the bit of glow on the hammer. However, what is it that that gnome (?) smashed? Also, I personally am not a big fan of plain white eyes, but they look alright.
fuzz: Love the shading on it, and the hands (right more than the left). His left leg looks a bit awkward, and in general it's hard to determine which leg is which (unless you base it off of the arm positions), but otherwise, nice pic. Background is a bit plain though. Is it from a game or a movie?
And I'm spent. Lots of good stuff on this page.