His toes are pointing the wrong way -- almost as if he's standing backwards knee and feet-wise. Also bring his crotch down a little, like you did his chest bottom to get a bit more change.
Finally, I'm not sure if he's trying to breathe heavy or just clenching his muscles, but either way, you need to commit to one or the other. Take a look at Megaman X and his stand animation. He's got a similar-ISH stance. Pay attention to his legs and his knees as well as the positioning of his feet/toes.
