Once again foiled by a buggy mission. Spawned into the first area, ( solo Titan, strand build ), killed all enemies, continued up the ramp, dropped through the hole in the big orb, followed the path, you reach a big chasm, on the opposite side is a big sliding door, well not only was the sliding door there, but also a barrier. Game over. I've uploaded the video to YouTube ( first time doing this so hopefully the above link is right, it's the only link I could find for this vid ).