Some thoughts:More contrast!Work on the readability. I have no idea what's going on The colors are too similar.
You should read http://pixeljoint.com/forum/forum_posts.asp?TID=11299http://androidarts.com/art_tut.htmContrast is basically the difference between two or more colors, if put very simply. Left has high contrast with the background, the right color has low contrast with the background.In Art, and pixelart especially you are rather limited by how much you can put on the screen. So more contrast is generally better because it helps with defining things and readability. (I'm sorry if this is wrong, but that's how I understood it)