This is a re-design of a book named Paper Towns. Just for practice, I've re-designed the cover.
Here, I can't notice any problem with the elements I've placed, but it somehow looks little cluttered or forced. My guess about problems is:
Overall composition isn't balanced. Since the mountains on right side are big, weight of overall design seems to be shifted on right
The book title (PAPER TOWNS) doesn't look much readable (looks blurred) and also seems misaligned.
Can these things be corrected?
EDIT: I did a few changes after reading answers. Changed size of paper elements.
Now content looks a little more balanced (at least to me). But bottom part still has problem. To me, it seems like it is interfering with yellow curve, and also there seems some unnecessary/unbalanced empty space above it. Can it be fixed?