2D - Spotlight and shadow

Hi everyone,

I've been having some trouble in the process of creating my 2D game. Here is the thing, i want to create a light source on the top of the screen, blocked by some rocks and letting only go through some light (a bit like that : http://www.ensci.com/blog/fablab/files/2011/11/fort-trou-enfer-puits-lumiere.jpg )

But here is the problem, i'm using a "Spot" light but it's impossible to cast shadow, i have this message : only directional lights have shadows in forward rendering. So i done some research, saw that we have change the camera settings and the player setting but it's doesn't disappear.

I tried some other things and ended up with this http://nsa34.casimages.com/img/2014/04/01/14040108075299565.png

As you can see in the "3D" camera, i have the shadow casted well but not the game. Any idea how to do what i want to do ?

Thanks :)