Updated.
Lar: You're a genius. The lack of centralization or focus or something was bugging me, though I didn't realize it. It still needs work, but I'm much happier with it now, overall.
Adam: I tried to improve his legs, and I think it worked for the most part, but they're still not entirely doing it for me. I keep getting closer, though, so I'll work on it. The koopa's proportions were intentional, so I left them as the are. If others find it distracting as well, though... I'm open to opinion.
ceddo: I left the bricks for now, though I agree with you. Its just that without them, the background's a bit plain, and I'd like to avoid adding colours as much as possible. Again, I'm open to opinions regarding how to fix this...