I am somewhat of a newbie, so I'm not incredibally surprised you thought that! Thank you for the critiques. When I have time later this week I'll take another look at him, see if I can make some improvements.

Hm... I don't know... When I saw this on the main page, "newbie" immediately came to my mind. Mainly because it... well... kind of looks like something I'd see a newcomer pixel artist do. It's not very detailed, and seems to have a bit of a color issue (not including the legs); the highlights on the red aren't different enough from the base color to be easily distinguishable, whereas the shadows contrast a bit too much. I feel like you should add another shade there and reduce contrast to give Spidey some depth (minus the legs, again; they're decently done AFAIK), and also remember to place the shading correctly so he doesn't look flat. Some hue-shifting would be nice too 

Thank you for the feedback! I tried making the shadows more purple, and I think it helped.

I think the pose is quite good, but it would have even more depth with some hue shifting when choosing the colours. At the moment, it is very "one hued" (as in there is only one red and one blue, perhaps adding dark, less saturated purple shadows would be a good start?)