Hello @The_Dancing_Tabaxi!
First of all, nice work! I like what you're going for with it. You can feel the warmth of the sun and the smell of the sea. I also like how it seems like we just landed on that beach and now came across this guy. It's up to our imagination to figure out what comes next!
With that out of the way, I think I have a few suggestions. Some are things that might need correction and others are more ideas for you to consider.
So first thing is the anatomy, mostly small things on the arms. The way you connected the shoulders to the arm is actually not quite right. The deltoid connect behind the bicep and then the pectoral muscles go under the deltoid. So with this arm postion we would see the pectoral muscle wrap over the arm instead of under. And also the connection at the elbow on the arm on the right seems a bit thin. It might end up looking like this.
Next would be the lighting and shading. You have a few inconsistencies, with the big one being the character's cast shadow not going in the right direction. With the sun behind, the shadow should come towards us. And since the sun is also relatively low, it should fairly long and stretched out. Also you could play around with darkening the character since the sun is behind him, which would put his front side in shadows. And then you can use the bounce light of the sand (warm from the bottom) and the ambient light of the sky (cool from the top) to shade him) along with a rim light from the sun light. That might help make him pop even more.
Also, you have fairly defined shading while the rest is softer. Unfortunately this has the effect of calling attention to the clouds. Softening the shading on the clouds and strengthening the one on the character would put the focus back on the character. Personnally I like to keep the lights on the clouds more defined and soften them in the shadows, but you may have different taste. So maybe a bit like this would be the result.
