Use the vortex from clockworks room to make a strange 0g obstical, with killing bricks floating around of coarse. As far as i know no one has implemented this.
HERES ANOTHER IDEA PLANT A BOMB WHEN A DUDE GOES TRU A DOOR AND HE ONLY HAS 30 SECS 2 GET 2 THE OTHER OBY COURSE OBSICLE..o but sometins slowen him down...ZOMBIES WILL DEM! WAT DO U THINK!?