Thank you for reminding me properly of the atrocity that is this mission. This mission is as bad as Mission 1 of CL is awesome.
The big points have been mentioned; forced time limit to complete an objective, forced encounters with nigh-on impossible odds against hordes of Undead, another forced encounter that triggers another silly objective, etc. When I originally played this, I spent a couple of days struggling with this mission, trying to make some progress in it. I remember getting stuck because I had no idea what to do after the Undead overran everything that didn't involve Mercedes McBitch...oh, and one of the Undead isn't Undead at all. It's some green monster that shoots stuff at you and has a truckload of hit points. I actually managed to kill it, only to get "Mission Failed" because I killed somebody! That was the breaking point for me. I never even got to the sword.