potential spoilers...
 
 
I quit the mission once you head down into the basement area. It said it was saving and yet... I wasnt able to resume my game. I tried again re did it up until the point where you have to find the three cranks. I found two and then ran out of time.  So I quit again and, it said it was saving again, and yet still not resumable.
 
 
Am I missign something?

like deusoma said, it seems like they're designed to beat in one sitting, which isn't much to ask for considering the length.