HELP!!

Ok - so this was going to be a sweet photo of my son amidst the box-towers - but then I set my flash (too high) - seems I have forgotten how to use it in the midst of all this trying not to! So I completely blew out the shot. What can I do about it - can it be saved? Below is my attempt to bring something palatable from something disastrous, but I'd really like some pro tips ;D I don't have photoshop in any form, but am slowly working out how to translate photoshoppy type work into gimp and paint.net (and then Picnik). Can YOU help me?

Cx