Thank you for all the comments! And I will try to do the AA, but I haven't really quite got the hang of it... Will be fine though :) And as for the color reducing, I agree, it's quite a lot :) but I'm learning.

Yet again: thank ya'll!

This looks fantastic. Makes me think of some isometric RPG on the game boy advance, such as Megaman battle network.

You're very good, for someone who's new. However, I think the color count could really be reduced a lot- 26 for a sprite with about four base colors is a little silly. Try reusing the light blues of the jeans as the dark shades of the hair, using the lightest hair shades for the shirt logo, etcetera.

Welcome to PJ. This is a good start to be honest. There are a few issues. The fact that you didn't use antialiasing the outlines seem rigged. You can begin with putting a single midtone dot next to the broken parts on the rightmost outline (only inside the sprite, not outside). Also at the bottom of the red shirt, there's an issue called banding. The when the ends of the 3-4 pixel lines of each tone of red match, they create a perception that they're round within themselves.

I believe you can find some answers in Cure's tutorial here.