I like the concept, and I marvel at your ability to make such a giant bubble! Beyond that, this image doesn't do a lot for me. The walls and door are not especially attractive. The lighting and colors are not so great, and detail is lost in dark areas. Bubble is out of focus. Compositionally nitpicking: The light switch, or whatever, on middle right edge might have been cropped off. Don't worry, you still kicked my butt!