Thank you guys!
Actually, the godrays were made specifically for this demo reel. But yes, it's a nice and cheap way of doing VFX withouth blowing the engine or memory.
The trees are about 500 tris, with LOD for far away shots. The models are actually intended for RTS or side scroller games where the camera is somewhat farther away. But, eventually, you can also see how good it looks with an FPS game ;-)
I hope to see you guys around at our store!