Some of the 700+ images at this site

Pathways image by Craig Mullins
Another Pathways image by Craig Mullins

Maps
Ground Floor
Never Stop Firing
Lock&Load
They May Be Slow...
... But They're Hungry (left way)
... But They're Hungry (right way)
... But They're Hungry (both sides)
Evil Undead Phantasms Must Die!
Ascension
Ground Floor: Reprise II
Wrong Way!
Welcome, Tasty Primate
Wrong Way!: Reprise I
Welcome, Tasty Primate: Reprise I
Wrong Way!: Reprise II
We Can See In The Dark... Can You?
Happy Happy, Carnage Carnage
Feel The Power
A Plague of Demon
Beware of Low-Flying Nightmares
The Labyrinth
Need A Light?
Lasciate Ogne Speranza, Voi Ch'Intrate
Watch your Step
Lasciate Ogne Speranza, Voi Ch'Intrate: Reprise
I'd Rather Be Surfing
Warning: Earthquake Zone
Don't Get Poisoned

Weapons
Knife
Colt .45 Pistol
Walther P4 Pistol
MP-41 Submachine Gun
Broken M-16
M-79 Grenade Launcher
AK-47 Assault Rifle

Ammunition
Colt .45 Magazine
P4 Magazine
MP-41 Magazine
M-16 Magazine (empty)
40mm HE Cartridge
40mm Fragmentation Cartridge
40mm Projectile Cartridge
AK-47 SABOT Magazine
AK-47 Magazine
AK-47 HE Magazine

Monsters
Headless
Zombie
Phantasm
Ghoul
Nightmare
Rat-Thing
Ooze
Wraith
Electrical Sphere
The Big Blue Meanie
Skitter
Ghast
Purple Pod
Flying Reptile
Sentinel (Skinny Buddha Dude)
Green Ooze (Yuck Monster)
Giant Purple Mutant Hellbeast (aka Barney on Steroids)
Venomous Skitter
Greater Nightmare
The Demon

Crystals
Yellow Crystal
Blue Crystal
Orange Crystal
Violet Crystal
Green Crystal
Black Crystal

Crystal Dialogs
Yellow Crystal
Blue Crystal
Orange Crystal
Violet Crystal
Green Crystal
Black Crystal

Potions
Clear Blue Potion
Bubbling Red Potion
Thick Brown Potion
Pale Violet Potion

Potion Dialogs
Clear Blue Potion
Bubbling Red Potion
Thick Brown Potion
Pale Violet Potion

Treasure
Emerald
Silver Bowl
Silver Medal
Large Pearl
Alien Pipes
Silver Key
Gold Ingot
Gold Ingots (Eleven on Beware of Low-Flying Nightmares)
Diamond Necklace
Amethyst Ring
Sapphire 1
Sapphire 2
Ruby Ring
Gold Key (found inside the Lead Box)
Alien Gemstone

Other Objects
Copy of Mein Kampf
Chain on Never Stop Firing
Nazi Propoganda
Canvas Bag
Easter Egg
Red Cloak
Cedar Box
Flashlight (dead)
Red Velvet Bag
Nuclear Device in Pod
Lead Box

Death Dialogs
Banshee
Rat-Things
Wraith
Electrical Sphere
The Big Blue Meanie
Ghast
Purple Pod
Flying Reptiles
Suffocation
Green Ooze (Yuck Monster)
Giant Purple Mutant Hellbeast (aka Barney on Steroids)
Venomous Skitter
Greater Nightmare
Poison (Thick Brown Potion)

End Game Dialogs
Forgot to arm the nuclear device... tut tut
Escaped... but ran out of time
Escaped... no beacon... ran out of time
Escaped... ran out time before pick up
Escaped on foot
Perfect Ending
The dreaming god has awakened (still inside)
Bomb goes off (still inside)

Other Dialogs
Emerald
Large Pearl
Alien Pipes
Silver Key
Easter Egg
Cedar Box
Diamond Necklace
Radio Beacon
Amethyst Ring
Red Velvet Bag
Nuclear Device
Nuclear Device (can't arm yet)
Lead Box
Gold Key
Sapphire

Runes
Blue
Red
Green
Yellow

Official v2.0 Screenshots from Press Pack
Ascension
Beware of Low-Flying Nightmares
carnage doors open
demon infrared
good rat shot
Pathways Screen Shot
PowerPathways Screen Shot
skitters & shots
Witness Total Carnage
WOFDT.wraith.crystal.bodies
YEAH.bursting nightmare

Secret Areas
False wall on Lock&Load leading to Blue Crystal
False column on Lock&Load leading to teleporters
Lock&Load teleporter to ...But They're Hungry
Lock&Load teleporter to Evil Undead Phantasms Must Die
Happy Happy, Carnage Carnage teleporter to A Plague of Demons
Death room on Don't Get Poisoned

Demo Version A1 maps
Pathways into Darkness...
Pathways into Darkness... (Reprise)
Never Stop Firing
Witness Total Carnage

Demo v2.0 maps
Ground Floor
Ground Floor (Reprise)
Ground Floor (Secret Area #1)
Ground Floor (Secret Area #2)
Charon Doesn't Make Change
Come And Take Your Medicine

Miscellanous
Pathways Updater 1.1 - 2.0 PPC Dialog Box
Zimmermann Telegram (Coded)
Zimmermann Telegram (Decoded)
"Ninjas. I can't stand them. They're Everywhere"
Monster from Morbius's Id
Hieroglyphics
Sentinel forcefield
Dead Sentinel
Predator
Facing the invisible foe
Lost Tomb (1982) Cabinet Marquee picture
Scott Reed's The Last Odyssey (Episode 54)
Ad for Pathways Into Darkness (MacConnection)
Ad for Pathways Into Darkness (Inside Mac Games)
Ring of Seven Dead Ghasts
End Screen
Ghoul concept art
Cover of Inside Mac Games magazine (June 1993)