Attacking at the main facility

Here are some novel ways of tackling enemies at the entrance to the main facility.

Ambush from the cliff wall tunnel

One way is to ambush them from the tunnel in the cliff wall, a feature that's not terribly easy to see and which I didn't spot for ages. But watch out for a clever Elite turning the tables and coming up the tunnel from behind you; I practically jumped out of my armour the first time that happened.

Needling from below

An entertaining way of handling the nasty Elites is to drive down to ground level below the overhang, then get ready with your needler. When they come to the edge, send in waves of pink needles to blow them up one by one. Move as you fire, so you don't take too much damage. Occasionally an Elite will run down to you in rage mode, so watch out.