I don't see the problem with the closest part of the bridge being darker. It looks as if in a shade from those trees. On the other hand, the base of the bridge doesn't seem to go the whole width of the bridge, and consequently the bridge's shadow is misplaced.
Something like this: http://img157.imageshack.us/img157/6998/bridgefixuz6.png
beautiful colors! the values of the bridge are a bit strange tho...I feel the further part is too dark and the pillars are too bright for instance.. otherwise I really like it! good job!
Want to give some dough back to all those amazing pixel artists? Donations provide prize money for contests, help cover hosting costs and support new initiatives.
Good work!