Nice idea, but a lot of hard edges on the cat, rough selections on the bridge, and you could have reconstructed parts of the cat's feet & blurred the shadow...

Agree with The master above masking needs to be worked on.

soften the edges of the cat and the shadow. plus i feel that the cat would be darker from having the light source behind it hope that helps

I see where you getting at, but work on the right railing on the bridge, it has rough edges. And the cat shadow should be directly in front with the other shadows, and soften a bit. Other then that, great work.

in an attempt to soften the edges i think you just blurred the entire image.. instead try going around the edges with a soft layer mask or eraser so that the fur looks more realistic

I'm not sure what it looked like before but ponti is right. It's too blurry now.

I love what you tried to create... if you not sure what people mean by edge softening etc. feel free to message me and i will explain and give a couple of ideas how to go about it... GL>