My 5 yo and I weren't seeing eye to eye on what to do with this picture, SO, I did one for her and one for me.
My Version:

In Gimp: Cropped, adjusted levels, did an unsharp mask, added two textures as layers and set layer mode to overlay, created transparent layer, did a large oval selection until the circle was outside the picture, inverted selection so only corners were selected, filled with black and lowered layer opacity to create vignette, flattened.
My 5 yo's version:

In Gimp: Cropped, Filters - Render - Clouds gave me the funky colors, selected the sky and colorized to get the blue color, Filters - Lights and Shadows - Supernova created the sun and rays , Filters-Distort-Iwarp gave me all the swirls. Flattened.