That's some really clean vectoring... love it! And the bubbles look amazing!
My only comment would be the text you incorporated. It just doesn't blend in with the image, somehow. As though it doesn't really belong here but is a piece of something else. But that's just my impression. Maybe I'm wrong.
Overall, though, I love the simplicity of the wall. It's greatest beauty is in the impeccable execution.^^
Great job!
--Scarlet