Yesterday i played that bonus map but it got 5/10 out of me cuz :-
the suroundings made it look like it was in a box.
the cutscene had no dialog.
too many enimes at one time.
when I got to the end nouthing happened
the objectives did not show at the top of the hud like noemel
here's how to get it working go to anywere in the campeigh mode then press ' then type open OMT_01A (make sure in cap) and then your there (make sure you have followed the insrtctions.