I think the anatomy could use a bit more work, but the main problem I have is basically structure. It doesn't seem like you're trying to build shapes or form. It seems by far your biggest weakness.
You need to work a bit more on values, volumes and shapes to understand how things really work and how light affects volumes. For now it seems to me like you're just using some lighting you've seen on some other paintings without really understanding it. A perfect example are the legs : they seem completely flat.