The higher grass and the tree (as well as the characters and UI) have a higher detail degree as the normal grass and the rocks (which I very like). Because of this it looks very unfinished for me, so I can't really crit it now (personally, I like the flat shading more than your detailed work, but it's just my opinion). Could you please elaborate your intended style that we can crit you better?
* The player sprite lacks a bit of contrast and definition. In 100% view, first I thought the beard is his head. Maybe a other color of his face (or coat) would help to clarify this.
* The shadow of the skunk (?) looks wrong. I'm not a expert for shadow casting, but I think if should be in a different angle than it's now.
* The shadows of the gems (?) should not be 100% under them because the light comes not directly from above. But since it's a game it may be better to collect them (and therefore have a inconsistent global illumination)
If this should be a real game, every sprite has to be drawn two times because the light comes from the top left. If would be more consistent if the light source would be straight from the top.
Good start, keep pushing