Hmm, I know he's supposed to be centered, but maybe have a little less negative space in the background? Maybe either drop out just a little or make him slightly bigger. Maybe some more defining shadows along his suction cups (even though there's a lot of them, I can see that). Other than that, it's looks great--the outlining, overall shadowing, and color scheme is fantastic... Ooo, symmetry and composition are good too!
Thanks for your comment. The reason for there being alot of ('negative') space is for when it prints on a wrap-around frame. The majority of it will be cropped out, leaving my main image from being cropped also. Note: my signature is not in the bottom right-hand corner, or it would disappear on the final print. Suckers: Sorry no shadow there as it would ruin the simplicity. My style, my choice.
Ah, I see, well that makes sense. And I can dig the whole simplistic style, so that's cool too--there were just a lot of cool details going on, so thought maybe you'd want to add shadow, but it looks good as is, and like I said, I can for the simplicity
Thank you. I was looking at several images of octupus's, as one does, and noticed that the sucker-side of their tentacles is a different colour or hue from the top-side. So I followed this method, for this literary character.