Thanks.

: I did the same thing a few years ago.

Seems like more people have been trying this sort of thing than I expected!

: Managed to pull it off so far on Pillar of Autumn through extreme luck

I had a tentative go at that today, but the bit where you get to the stairs is going to be pretty tricky I think. Maybe the toughest bit.

: Halo was simple because I killed my marines and skipped 2 of the 3 areas
: in the last portion

Skipped them? In that case how did you get the level to end?

: Silent Cartographer was a slow and really drawn out
: experience but I took advantage of pre-set warthogs loaded with marines to
: ambush enemies in known enemy spawn areas

Sneaky. Is there a standard name for that tactic? 'Marine camping' perhaps?

: AotCR I took advantage of the
: no-enemy glitch from jumping down from the first bridge

Well, that's certainly going to lighten your workload.