I think you are doing good job, I like the double curve mechanic, but I have to be blunt here, In my opinion, I think the game looks like a great flash game, nice student project, but not a clean, polished, feature quality iOS game.
There are too many little things that bring the overall quality down.
I feel the background is the biggest issue here, its really difficult to make a big detailed image like that look good, right now I don't think it looks good/professional. I don't think I have seen many blurry backgrounds recently, Can you find a good, featured game that has used a blurry background art style?
Also the curvy bar is now blending in to the background, I though it hadn't spawned the first time I opened the game.
Look at the current list of Best new games/Games we love. There is a very clear/clean art style across the board.