Haven't critiqued anything in a while, but I suppose I can take a crack at it.

I really like the choice of colours, they work well together and seem to be a bit depressing, which seems to fit the piece well.
The background textures are interesting without being overbearing, but the lack of texture on anything but the background seems like a strange choice to me. I'd add some textures to the other elements to tie things together, but it's more of a preference as the background textures are subtle enough that they don't clash with rest of the work.
The clock is an interesting element, although I'm not fond of the placement in the picture. For some reason it looks like it's attached to the canine's butt to me. I feel like it's symbolic of something, but I've never been good with symbolism though, so all I can say is that I do like the visual interest (although I'm curious as to why it's ticking backwards).

I really enjoy the piece conceptually, but I really don't like the way it's laid out compositionally. Some of the most visually interesting elements like the pool of blood and the blinking eye feel too close to the corner and my eyes just sort of run out of frame. My solution would be to simply pan the fame down and right, but there's probably more creative solutions than that.

Overall I like it a lot. It has this somber feel to it that makes me ponder life in general.