Reading these draft terminals full of polite, entirely sane Durandal feels more than a little bit wrong. Interesting that vacuum was slated to be one of the environmental hazards in the Citadel...

What's in the names? Bob-B-Q writes:

Old level listing. Might be some fodder for the WiaN? section here.

Here We Go Again
The Slings and Arrows of Outrageous Fortune
Charon Doesn't Make Change
What About Bob?
One Of These Days I'm Going To...
Come And Take Your Medicine
Eat It, Vid-Boy! (why the spelling change?)
Six Thousand Feet Under
S'pht Happens
We Can Breathe Vacuum, Can You? (but can they see in the dark?)
Feel The Noise
Nuke And Pave
Curiouser And Curiouser...
If I Had A Rocket Launcher I'd Make Somebody Pay
Would You Like Fries With That?
Death by Bungie
I've Always Wanted To See An Assault Carrier Explode
99 Canisters of Napalm On The Wall... (who's the TOZT-iest of 'em all?)
Everything Counts In Large Amounts
My Own Private Thermopylae
Only By Great Risks Can Great Results Be Obtained (Sun Tzu said that!)
Women And Children First!
Barbarians At The Gate
Requiem For A Cyborg
Oh S'pht! (this level naming theme is oddly pfhamiliar...)
With a Mellon? (possible reference to a Monty Python sketch)
All Roads Lead To Sol...

TWF <zea@uw.edu> writes:

Just noticed this at the end:

iv) Never Eat Yellow Snow (#27)
Environment:
Shapes: pathways (green pathways pyramid, orange columns, bones, etc.)
Monsters: headless
Items:
Notes: secret exit from #26"

So originally Marathon 2 was meant to have a secret Pathways throwback level? Reminds me of M1A1.

Bob-B-Q <pwrofs7n@roadrunner.com> adds the following to TWF's comments above:

Yup.

Sayeth the Scrapbook: An early plan called for Marathon 2 to end by dumping the player in the first level of Pathways Into Darkness, thus making the connection between the two games explicit. Plans changed, though, and the only remnant of the idea is a vague allusion to "an entirely different reality than the one of the starship Marathon" in the Marathon 2 manual... Infinity's storyline defies simple description, relying as it does on multiple realities and alternate timelines. Early versions of the story included a side-trip to the world of Pathways Into Darkness (since it had been cut from Marathon 2) but this idea was eventually shelved for good.

Another point of interest: the Armageddon Beast was slated to appear in M2.

On the subject of the secret level 'Never Eat Yellow Snow', chiasaur11 writes:

It's an old joke, the yellow snow thing.

Yellow snow is, well, snow with human urine in it. It's a traditional warning.

Bob-B-Q <pwrofs7n@roadrunner.com> notes the following in the Marathon 2 narrative:

When one of foreign speech casts a papyrus yoke upon the sea,
Bethink you to keep the bleating goats far from Euboae.

Which became part of a Thoth terminal on Beware of Abandoned Rental Trucks, namely:

Glyphs never understood while
     [?young?alive]
now reveal the end of my creation:

When one of foreign speech
casts a [?papyrus] yoke upon the
     marsh,
Bethink you to keep the
     [?bleating goats]
far from Lh'owon.

Discussion on the Thoth section many years ago correctly identified this terminal text as being from Aubrey de Selincourt's translation of the Greek historian Herodotus (the common Penguin Classics version), page 531:

"When one of foreign speech casts a papyrus yoke upon the sea,
Bethink you to keep the bleating goats far from Euboea."

But as Bob-B-Q notes:

Bungie misspelled 'Euboea' again, too...