Wow - just noticed this was a new personal best for you - congratulations!! This was one of my top choices for the challenge - really pleased to see this did so well.
Tons of visible JPEG compression, though I am not sure how, as your filesize is 141k, which should be sufficient for a nice smooth image. It is possible that you could have been saving your working copy as a JPG. Repeated opening and resaving of a JPG could cause this. Always save working copies as an uncompressed format, such as TIF or the native file format for you photo editing application. (Such as PSD for Photoshop or PSPIMAGE for PaintShop Pro)
Looks like golden glass stairs. Good idea. You have got an eye. This picture has a lot of potential. I imagine it with dark blue sky or at night. Very nice. Good luck.
Nice perspective with a somewhat unusual but very effective composition/framing. The gradation of color really makes this an excellent image. Could you have lost the solid portion along the top edge? 8
Very cool - I like the way it moves from concrete (literally) to nearly transparent, almost sketched in nature. Very nice interpretation of the challenge.