J
Looks pretty good to me, though here are my thoughts:
1. Either do all black outlines or none. And if you do black outlines, do it the same from sprite to sprite - meaning, if you did just the top and left borders on something, do that the same on all sprites.
2. The dark grass and tree leaves textures are a bit harsh looking.
Thanks for the feedback and will keep this in mindI believe the trick is, instead of doing black outlines, simply outline the sprite using a darker shade of that section's color.
Try to avoid orphan pixels as much as possible, they will only generate noise.