Awesome! Please keep it up!
By the way, have you made any progress on the Wily Tower 1 background? I was looking at it the other day, and I may have found a solution to the problem. At the end of the level there is a long, straight section that only has only one platform that sits low on the screen. This area is at the lowest point in the level, so I would imagine that you would be able to get most of the lower section of the background there. Also, in order to get the part of the background that is covered by the platform, in the next few screens there are holes in the foreground wall. I think that they are the same height as the aforementioned platform. Using this setup, I would think that you could piece together the lower part of the background.
Good luck with the rest of the maps. I will be looking forward to seeing them.