Your anatomy is still fairly off on this character.
I've taken account of your most recent edit and IrresponsibleFreelancer's as well, since they made some changes that adjusted but still did not fully correct the problems.

If you look at the original (your most recent edit) on the far left, you can see the skeletal wiring is out of proportion from one side to the next.  The character's right arm is longer while their right leg is shorter.  The pose could account for the leg perhaps but not the arms. Both portions of the arm are longer on the right side as you can see by the color associations I have marked.
IrresponsibleFreelancer's lengths are closer together on the arms.
On the first image I drew anchor lines for the head/neck and the shoulders to the floor.  You can also see the relationship of the knees with the position of the head this way by looking off of the dark green lines.  In order for a pose like this to work the shoulder, hip, and ankle of the right leg need to be lined up very closely or the character would simply fall over backwards.
You can see the angle of the shoulders with the head are very right side heavy as well.  The left side shoulder is much longer.  The angle and positioning of the head and neck suggest a backwards lean.

All of these things come together to make the character look as if he is falling over.

The best way to fix this aside from redrawing him, is to pull his anatomy into better alignment and then redraw that to make it work.

A very quick reallignment:

I started out only wanting to learn how to do pixel art as well.
Nearly every person who has spent time learning how to pixel art will tell you the same thing.

General art principles and skills are incredibly helpful. The time spent practicing drawing will naturally bleed over into direct pixel art development.

You have some confusing elements to the composition of your scene.
Is the viewer positioned above watching the ship below?  If so, then the planet is presumably below the ship and it is flying over?

With no light source behind or below the planet it wouldn't show much of a radiant haze for the atmosphere.  Unless the planet itself is glowing.
Any light you see in space (anywhere actually) is reflecting off of something.  Even when it is passing through, the color you see is hitting particles and bouncing off heading in your direction.  Most of these pieces that show planets with a haze around them, are showing the atmosphere of the planet.  It is reflecting light from a nearby star usually. How bright it is and how large the haze is depend on both the angle of the light's approach and the general size of the planet.

You have to think about how "high" the atmosphere is on a planet like this for you to nail down a sense of how thick that haze should be.
It wouldn't all be a perfect spherical bubble around the planet either.  You would be better to try to capture a feeling of fog perhaps.
Brightest at the edge of the planet where that atmosphere would be the thickest (more to bounce off of) and fading out gradually.

Suggestion, shrink the size of your gradient bands, they feel huge.
Try to bring your contrast down some between each color.
Try not to be so perfectly circular on the gradient boundaries. Those long straight lines stand out to the human eye really heavily.

Very nice.
Cleaner than my sloppy version and it has a subtle ambiance to it that helps the mood rather than taking attention away from it.