I made a similar thread back around Christmas, because I had a scene that was too hi-poly for the BGE. Now I’ve scaled it all back, and I’ve got the whole thing done in 9000 faces (300 objects, none of which are dynamic). I’ve scaled all the textures down to 64x64.
But it still doesn’t work. First I deleted all the textures. Then I started deleting faces, and couldn’t get it to run until around 900 faces. Why could this be? I have 2 gb of RAM.
.blend file:
www.savefile.com/files/432324
hm…well it crashes for me too, i tried joining all the objects and that didnt help, i tried reducing polycount (its around 12k, not 9k, you gotta consider stuff on other layers too ) and it still crashed, but if i deleted everything it didnt crash, so thats weird
I seem to remember I already debugged your old scene http://blenderartists.org/forum/showthread.php?t=85218
It’ll be the same problems here, invalid parenting paths and Far too many doubles. I’ll take another hour or two to debug this one, but I’m Sure it’s errors in your blend and not the size. In future you may want to create far less objects in your project by joining several related meshes into one, it makes for ALOT simpler a debug 
I’m going through your file now.
Just as I said, the main problems were doubles. Fixed it (In alot quicker a time than your last one) and here it is
http://www.savefile.com/files/432462
(Wups, posted it on your first topic)