I'm probably the only person that would bring up this small detail but it is relevant here. With your radial gradient, you have what's called banding going on. If you look closely you can see the white to blue transitions resulting in bands of the different colors that make up that particular gradient. To fix this issue, click the gradient tool and be sure to select the "dither" option. Then re-apply the gradient as you did before. Essentially what this does is it smooths out the gradient which results in a seamless blend of colors.
Alternatively, you can also use the layer styles panel for the layer that contains the radial gradient. simply double click on the layer and you'll be greeted with a new dialog box. The particular style is called gradient overlay I think. Though using this method is somewhat more complex then the gradient tool, it does offer you more control as to how the gradient will be applied to your graphic.
The only other things I would change are the minimize, maximize, and close icons at the top right of the interface. Think about this, are those icons really necessary for this interface? Also, you might want to increase the size of the player controls. It will make it easier for those who are visually impaired. Usability is just as important as visibility.
Overall it is quite the nice looking graphic. Your colors mesh with each other, and the green glow around the buttons do draw attention. In looking at it again, it has a 3D quality to it like it's extruding out from the background. You accomplished this by the use of your gradient Did you mean to do that? If not, you'll know how to do this the next time you're going for this appearance. Hope this helps.