What on earth makes you think this painting failed? Dark night scenes surely are very difficult. I think you've done well in holding back the highlights. Maybe you need to explore the different shades of gray some more and lighten up teh whole scene a little bit so that you get more room for the really dark patches again. This will allow you to build depth.
You do what you like. Finished it is not, but neither is it failed. Not at all.
It's not about how many breaths you take; it's about the moments that take your breath away.