Heh, I see where from this map is inspired: GITS - Ghost In The Shell , near the end of the movie, when Major Motoko Kusanagi battles against a tank, when Bateau shows up in the last second and hoses it with a *cough* small gun.
I don't see any "Tree of life" illustration on the wall up the stairs . It is a bit dark though, and it would be nice with more blown off peices, like in the movie after the tank-battle (maybe broken glass-roof too). But it's your choice if you want the map to look like before or after the battle, heh.
I wonder if it's possible to have a chopper fly by from time to time, since the Combine helicopter is almost the same as the choppers seen in GITS, just for the atmosphere.