Sit boy!

Nicely done, I like the red effect.
The shoes, though a minor detail, I think should be redone.
So much detail is placed in the whole body, yet when I see the feet...not much attention was payed there.

It also bothers me how I don't see a tail. In this form of pose (If he is on the ground)
A tail should be between his legs (Or if he is jumping) It should be shown slightly under his right leg.

I feel like I may be nit picking, but those are the things bothering me, everything else is wonderful!

Nice work.

This looks very clean and crisp, very sharply detailed. The anatomy looks exaggerated while still realistic, rather than some ridiculous disproportionate musculature out of a Rob Liefeld comic.

The parts in red look somewhat unnecessary, though, and while they don't exactly hurt the image's effect, it might be better to get rid of them.