It's clean and sleek; it is fine for now. What I'm more concerned is how this background's going to be implemented on the webpage.
Depending where the content will be, I have a feeling that your contrasting, green circles might be distracting. Maybe increase their opacity a bit?
Lastly, though it might not sound nit-picky, but those circles . . . If you are trying to make them look more like spheres, they're not. They're almost look like partially-cut spheres. You might want to fix that if spherical shapes are what you are intending.