I would like to have seen this one bigger. Smaller images are always a challenge to judge. I think you had a good concept here with the macro feel. This type of image might work under the abstract challenge as well.
there are some interesting textures there, but the image size is too small for that to be a major impact and since that's what the entire composition is relying on, i'm going to score this pretty low. sorry.
are these sun spots, or what? just kidding. I'm sure you'll hear this a lot: make your picture bigger. Size it to the allowed dimensions. At this size there is not a lot viewers can see.