Below are the full names of each level as they appear in the Map data fork (demos and full game). Like Marathon you'll note that some of the level names were changed and traces of the original name can sometimes be seen (marked in yellow bellow) at the end. In some cases a level name appears to have been changed several times. It's not hard to work out the original names in some cases but for others the mystery remains.

Note that Bungie used a single character to represent an ellipsis. However in the list below the ellipsis is represent as three dots. Six dots = two ellipses.

Note also that the names as given in the Map data fork do not always correspond with those listed in the application resource fork.

Level names from the data fork of the Pathways Into Darkness Demo Version A1 Map file:

Pathways into Darkness...
Never Stop Firingns To Dog First!
Witness Total Carnagehit 2 in top down

Level names from the data fork of the Pathways Into Darkness v1.1 Map file:

Ground Flooro Darkness...
Never Stop Firing
Lock&Load
They May Be Slow...
...But They're Hungry
Evil Undead Phantasms Must Die!!
Ascension...
Wrong Way!
Welcome, Tasty Primate
We Can See In The Dark... Can You?
Feel the Power
A Plague of Demons...
Beware of Low-Flying Nightmaresares
The Labyrinth
Happy Happy, Carnage Carnage
Need a Light?Slices!
Lasciate Ogne Speranza, Voi Ch'Intrate
Watch Your Stepll Who Enterteranymore......"
I'd Rather Be Surfingosein here?y?
Warning: Earthquake Zoneine...age
Don't Get Poisoned!re Tread
Please Excuse Our DustAll!
But Wait!- That's Not All!
Where Only Fools Dare Tread
Ok, Who Else Wants Some?

Level names from the data fork of the Pathways Into Darkness Demo v2.0 Map file:

Entrance To Hell
Search Me!
Carnage from Above

Level names from the data fork of the Pathways Into Darkness v2.0 Map file:

Ground Flooro Darkness...
Never Stop Firing
Lock&Load
They May Be Slow...
...But They're Hungry
Evil Undead Phantasms Must Die!!
Ascension...
Wrong Way!
Welcome, Tasty Primate
We Can See In The Dark... Can You?
Feel the Power
A Plague of Demons...
Beware of Low-Flying Nightmaresares
The Labyrinth
Happy Happy, Carnage Carnage
Need a Light?Slices!
Lasciate Ogne Speranza, Voi Ch'Intrate
Watch Your Stepll Who Enterteranymore......"
I'd Rather Be Surfingosein here?y?
Warning: Earthquake Zoneine...age
Don't Get Poisoned!re Tread
Please Excuse Our DustAll!
But Wait!- That's Not All!
Where Only Fools Dare Tread
Ok, Who Else Wants Some?

Max Etchemendy <mxetch@yahoo.com> write:

I just thought I'd mention something about the original level names for PID. Like "Beware of Abandoned Rental Trucks," (Marathon 2) "Beware of Low-Flying Nightmares" replaced an earlier name that was longer by four characters. Thus my guess is that "Beware of Low-Flying Nightmares" was also at one time "Watch Out for Low-Flying Nightmares."

As you can see below it does fit:

Beware of Low-Flying Nightmaresares
Watch Out for Low-Flying Nightmares

Max continues:

The really interesting part to me is that Bungie originally titled "Beware of Abandoned Rental Trucks" to be a play on the =earlier= version of the corresponding PID level. You'd think they'd have named the Marathon level after the version of the PID level that appeared to the public in the first place. (i.e. without changing their minds later.) Maybe they just couldn't make up their minds. :-)

Max is referring to the fact that the title of Jason Jones' level "Beware of Abandoned Rental Trucks" was originally longer and was probably called "Watch out for Abandoned Rental Trucks":

Beware of Abandoned Rental Trucks|cks|
Watch out for Abandoned Rental Trucks

Thus it would seem that both level names went through the same name change process. As Thoth would says: "circumstances are cyclical"

Andrew Nagy <removed0@hotmail.com> writes:

It looks like "Watch Your Step" has been through two revisions of "Lasciate Ogne Speranza, Voi Ch'Intrate" as well as something about Kansas. Of course, all this is totally screwed if there's a null character indicating where the actual name ends. I'll try to decipher them because I think I can:

?????????????????????????????????????(?)..."
I don't think we're in Kansas anymore......"
Abandon All Hope, Ye Who Enteranymore......"
Abandon Hope, All Who Enterteranymore......"
Watch Your Stepll Who Enterteranymore......"

Andrew goes on to point out that the level name Entrance To Hell from the data fork of the Pathways Into Darkness Demo v2.0 map file is connected in theme to the level name "Lasciate Ogne Speranza, Voi Ch'Intrate" which translates to, "Abandon Every Hope, All Who Enter Here" and is the inscription above the gates of Hell in Dante's Inferno.

As pointed out above the level names from the data fork of the Pathways Into Darkness Demo v2.0 Map file are

Entrance To Hell
Search Me!
Carnage from Above

Yet when you play the demo the actually level names are:

Ground Floor
Charon Doesn't Make Change
Come And Take Your Medicine

These appear in the resource fork of the Pathways Into Darkness Demo application (STR#2021). You can still find the level names Entrance To Hell, Search Me!, and Carnage from Above at the end of the full list of level names in STR resource #2018. All rather odd.

Calandra "Callie21V" Witter <callie21v@hotmail.com> writes concerning the original level name of "Need a Light":

The original title for "Need a Light?" seems to be -

Need a Light?Slices!
It Dices! It Slices!

...which constitutes an apt description of the Big Blue Meanie.

Like "But Wait!- That's Not All!," this phrase is most often heard in infomercials. Perhaps it was replaced due to the similarity.

The strange part is that the much more common variant is "It slices! It dices!" But then, Bungie always did have a hang-up when it comes to quoting obscure languages. :)

Well here is something I completely missed and which doesn't correspond with what I wrote
about the level names from the data fork of the Pathways Into Darkness v2.0 Map file (see above).
Unfortunately I am no longer able the recheck my analysis of this.

On the Story forum xcalibur and Mark Levin draw attention to the
mispelling of Where Only Fools Dare Tread in version 2 of Pathways Into Darkness

In version 2 the level is called Where Only Fool Dare Tread. Thanks to Mark Levin for the
screenshot.

In version 1.1 the level is correctly called Where Only Fools Dare Tread. Thanks to xcalibur
for the screenhot

You can also see the mispelling in HB's Pathways Into Darkness Walkthrough which uses version 2.
So obvious when you see it now.

What is odd about this is how the level name got changed between 1.1 and 2.0.
Typically mistakes like this are corrected in later versions of a game not introduced.