A lot of the same things apply as when critiquing and improving realistic art: Composition, balance, how the eye travels around the picture, does the art evoke emotion or thought?
With your painting, you have the golden ratio split (or something very close to it), which is good, but you don't have a clear path for the viewer's eye to follow around the picture. The first thing I look at is the largest "box" which seems to be pointing to the upper right corner, which is all well and good, because there it meets the first squiggly "S" shape which leads to the next to the left of it and the one to the left of that one, which then leads... out of the painting (bad, you don't want to make the viewer's gaze leave the painting halfway through). And at the same time, I'm distracted by the "tentacle" on that first "box" thing that leads to the left instead of right where my gaze initially wants to go. And the result is a bit of a disjointed experience.