Looks pretty good. To add onto Krunch's point, the top right doesn't make sense, because I would think the top left would be close to the same colour as the top right, since the light source is right in the middle.
Try working on the text, because text is very important, and I'm not feeling the one you have now, it just seems very simple and the colour's out of place.
Overall it is simple, yet looks good, good job