The first is the opening sequence and Commander Shepard's trial.
Here is the rendezvous with the Normandy where Shepard and Anderson have to hold the pickup zone from Scions while waiting for the Normandy to arrive.
Finally here is part of the beginning of the fight with Garrus and Liara on the Salarian home world of Sur"Kesh, to save the Krogran Female. Also shows the biotic power Nova. Looking at it now I can see that Nova did have an affect unlike what I said yesterday. Obviously I just didn't see it while playing the game. The ending is on my previous Mass Effect 3 Demo post. The squad point system for Vanguard and the Assault Mastery is shown also.