Actually, it would be more accurate to say this is the first real mission. This is the first one where you have an opponent AI who gathers and builds. As soon as you exit Khyber, he gets activated. Success in this mission largely depends on two things.
1. Getting all affairs in order before use the Khyber exit by the shrine. This means finishing all quests, spending all exp/dragonshards, as you will soon not have time to do so.
2. Constantly using all your squad abilities in combat. Make sure all auto-use abilities are on, and fire off the rest as best you can. Simply attack-moving will probably have you lose most of your forces. Using all abilities as fast as they recharge, you won't take losses at all.
Edit: dwmattcv, you did follow the ghost and get the idol, right? The barrier is up til' then.
Post edited August 20, 2012 by IronWyrm