The palette is great! I like the little lights on the buildings and how each one has a unique shape to 'em. I also like how the railing frames the picture.
It's minor, but I'm not sure about the placement of the twinkle/venus. It seems like it should be placed somewhere eles to draw the eyes towards the focus of the picture. It also seems like there should be more light purple buildings behind the dark purple ones to give the picture more depth. Otherwise, it's pretty groovy.
Yeah I think you're right. I placed it exactly on the central vertical axis of the canvas, and wanted to use the almost symmetrical pillars of the refinery as composition to reinforce the position of Venus.