The Undoing

I genuinely think this is a really nice piece (structure, style and composition are good) but as others have suggested it lacks a little "zing" - a little post-processing would work wonders, I'm sure.

If you don't mind me sticking my nose in... I would suggest you examine the black and white "Levels" of this (i.e. the "histogram") in your image editor and give the white end a boost. This will bring out the lighter areas and generally beef up the colours too. You could pep up the saturation a little too if you want more colour. I often do little tweaks like this on my own work and do believe it can work wonders on a piece that has rendered a little dull or dark.

Hope this helps.