I had originally intended to, but I ran out of time for the initial assignment. Now that you mention it, though, I think it's long past due for a revisit. Make it a little more reverent and a little less 'whoops gotta put something in my portfolio here have a Vishnu.'
I like the background, actually. I mean - Vishnu. God. Simplistic background, so as not to take away attention from, y'know, his godliness, really works for me. I love the overall contrast in the colour scheme, how the dark blue and black, the brightly-coloured decorations he's wearing, and the white almost-aura all make Vishnu stand out more than he would on a more detailed background. For the same reason, I like the hint of white designs on his face, and the whites of the eyes. In addition, I emphasize again, he's a god. He's allowed to stand in the middle of nowhere, in some realm where there's not yet a world. I'm not very knowledgeable on Hinduism, but I'm sure that's allowed.
Also: contemporary art of Vishnu is awesome. There needs to be more in the world. Brilliant picture!
Well, there's is some charm to the half-assed. I don't think you should do anything more it it. It's simplicity is nice. If you do more it might look too complex. I think it's simplicity makes it pretty.