Some, but not all, aspects of this look like a paintover of a screencap; it's a little hard to tell. In either case, I'm assuming you worked from a screen as a reference. So, let's talk about that.
This piece screams "ambition". That's a good thing! You wanted to get the full range of light and shadow, of opacity and translucency. It also looks like you made it a little harder on yourself than it needed to be by using a brush that smears too much, and by not working from general to specific. In the future, try squinting at your reference and seeing the broader "color shapes". Start with those, using a high opacity brush with blend/color bleed turned down or completely off. Once you've got that down, you can move on to higher and higher levels of variation and detail.
You don't have to always do that, but try it once. When you've blocked in all the color variation, you can use a blend tool to go in and blend colors into one another. This gives you another opportunity to check: How soft does this shadow edge really need to be? Your shadows are all of nearly identical softness, which makes the figure a little difficult to read. I think you'd get a lot out of trying that exercise once or twice.
Best of luck!