anywaaaysss...i was wondering if any of you guys know some easier ways to get the untouchables & the nothing special achievements apart from trying to pass the campaign/using the jesus room.  

if you have some ideas/tactics/could tell me which map is the best for this achievements or sth comment :D

cheers.

update:
so i got the untouchables achievement but i still have a really big problem finishing dead air on expert. the finale is killing me...quite literally. you have any ideas how to pass this damn thing? ;d