I think it's a good base, the shaping and everything -- should make a nice banner. The colors look very NES to me, which I think is good too -- oldschool. My only problem with it is that it feels flat -- I think it needs more depth.
For example, I made a 5-minute edit of the buttons (hope you don't mind), to show them to look a little deeper. I completely killed the NES feel, but I hope it gives the idea.

See, I used more colors to push it up a few levels. Notice how the highlight changes it's position by a pixel or two based on the position of the button -- by moving where the light reflects, it looks like the angle to the light changes, which also helps the depth a little.
With a bit more time, I'm sure it could be done even better.
Hope this helps.
