An excellent macro that must have been rather tricky to do. Fantastic patterns and colours. I like the composition, though I think cropping the top 15-20% off may have helped as I do not think that part of the image is contributing anything.
I like the idea of focusing on that distinctive join between bubbles. it provides some lovely lines that contrast well with the more organic shapes (and vibrant colours) of the surface above. I think a deeper depth of field would work better here but like it as is too.
Love the colours and simplicity of this photo, I also happen to love macro. Definately one of my favourites in this challenge. It's a pity just a teensy bit more couldn't have been a little sharper. Great Shot!!