Looks pretty smooth, and welcome to the forum!
I think some places could use some AA'ing, such as the inner edge where the side meets the front of the body and head.
The far foot could use a little more depth, I think. If the 'balls'
gradually get darker, with the darkest ball at the bottom, omit the one in shadow, you could make it feel like the foot is back more, and it would probably help balance the pose a little.
For some reason, I'd really love to see this animated, I can really imagine it in my head.. although I'm not asking you to, and it would be hard, I just think it'd be really neat, for some of the things I'm imagining.
I like 4th palette the best, and coincidentally, that seems to be the one you're currently using/working on?