I'm not going to give you much critique yet, as I feel you have multiple solutions to explore before needing help from us
Here's some homework:
- Make a bunch of recolors of this sprite. Change the palette, clothing color, hair color, eye color, etc. See if any of those recolors suit you more and if you can learn anything from exploring the color space. Have fun with this. Green hair, blue hair, red hair, anything goes. Make a space explorer version and a caveman version.
- Search a few games (Pokemon, Zelda, Earthbound, etc) that have similar sprites and try recreating this character in each of those styles. Try to find out why they do certain things the way they do.
- If your drawing skills are fine, try making some drawings on paper of this character.
- After all this, remake your sprite, using the stuff you learned.
For us to help you, be sure to post everything you do, even if it's mediocre in your eyes