Thanks for looking at it.
Did you really not notice any difference in player turning speed, between the small and big rooms?
The problem with 800x600 is that the graphics are made for higher res, so everything will look big and blurry in fullscreen. Running in a window is really not an option since the idea was to have GUI bars with text and stuff (and they would turn out very small). Plus, the idea was also to have shooter sequences which demands a larger "view" for the player (i.e. you won't see the enemy until he is in your hair, running in 800x600).
Oh, well. I guess it's sprite scaling time then.