There are some jagged lines. Keep in mind that simpler shapes usually work best.
The hands are a bit small. I don't know what the thing in his neck is, but it has a weird outline.
Does it have something to do with the back thing behind the arm? I thought it was a shadow. It follows the arm's shape perfectly and makes it hard to read.
Also, you don't need to separate everything with lines. The colors already do that job.
I think you should have picked the colors from scratch again instead of using the same ones as before.
The blue colors don't have enough contrast. It looks just like you just added some black to the blue for the shadows.
What helped me the most was downloading some sprites I liked, making a palette out of each one's colors and comparing each color (how much the brightness and hue changed) to the one next to it.