Firefox
Install the DownThemAll addon
Restart Firefox
Right-click this page and select "dTa OneClick..."
In the popup, expand "Fast Filtering" at the bottom and enter "steam" into the field there
OPTIONAL: In Renaming Mask text field put "*text*.*ext*" (This downloads the backgrounds with the file name as the name of background)
Click the "Start!" button and wait for downloads to complete (If you changed the renaming mask, some names will overlap and you will have to give the addon an option to continue (skip/rename/replace))

Chrome
Install the Download Master extension
While on this page, hit the Download Master icon in the top-right
Check the "Show all links" display option, then enter "steam" into the Custom filter field
Click "Download" and wait for downloads to complete


1... 2... 3... KICK IT! (Drop That Beat Like an Ugly Baby)

7 Grand Steps, Step 1: What Ancients Begat

A Valley Without Wind

A Virus Named TOM

A.R.E.S.

Ace of Spades

Afterfall InSanity Extended Edition

Agarest: Generations of War

Age of Empires II: HD Edition

AirBuccaneers

Alan Wake

Anna - Extended Edition

Anodyne

Anomaly 2

Anomaly Warzone Earth

Arma 3

Awesomenauts

Bad Hotel

Bastion

Batman: Arkham Asylum GOTY Edition

Batman: Arkham City GOTY

Batman™: Arkham Origins

Battle Worlds: Kronos

Beat Hazard

Bionic Dues

BioShock Infinite

BIT.TRIP FATE

BIT.TRIP Presents... Runner2: Future Legend of Rhythm Alien

BIT.TRIP RUNNER

Blackguards

Bleed

Blocks That Matter

Blood of the Werewolf

Borderlands 2

Brütal Legend

Call of Duty: Black Ops II - Multiplayer

Call of Duty: Black Ops II - Zombies

Call of Juarez

Call of Juarez Gunslinger

Cannon Brawl

Castle Crashers

CastleStorm

Chainsaw Warrior

Chaos on Deponia

Cherry Tree High Comedy Club

Chivalry: Medieval Warfare

Citadels

Cities in Motion 2

Cognition: An Erica Reed Thriller

Company of Heroes 2

Contagion

Cook, Serve, Delicious!

Costume Quest

Counter-Strike: Global Offensive

Crusader Kings II

Cubemen 2

DARK

Dark Fall: Lost Souls

Dark Matter

Day of Defeat: Source

Day One: Garry's Incident

Dead Hungry Diner

Dead Island

Dead Island Riptide

Deadlight

Deadly Premonition: The Director's Cut

Defender's Quest: Valley of the Forgotten

Defense Grid: The Awakening

Defense Technica

Defiance

Delve Deeper

Deponia

Deus Ex: Human Revolution - Director's Cut

Divekick

Divinity: Dragon Commander

DLC Quest

DmC Devil May Cry

Don't Starve

Dota 2

Dream

Droid Assault

Drunken Robot Pornography

DuckTales Remastered

Duke Nukem 3D: Megaton Edition

Dungeon Hearts

Dungeons of Dredmor

Dust: An Elysian Tail

Eador. Masters of the Broken World

Edna & Harvey: The Breakout

Electronic Super Joy

Empire: Total War

Endless Space

Escape Goat

Ether Vapor Remaster

Euro Truck Simulator 2

Europa Universalis III

Europa Universalis IV

EVE Online

Eversion

Evochron Mercenary

eXceed - Gun Bullet Children

eXceed 2nd - Vampire REX

eXceed 3rd - Jade Penetrate Black Package

Expeditions: Conquistador

F1 2013

Face Noir

Faerie Solitaire

Fairy Bloom Freesia

Fallen Enchantress: Legendary Heroes

Far Cry® 3 Blood Dragon

Farming Simulator 2013

Fist Puncher

FLY'N

Football Manager 2013

FORCED

Fortix

Fortix 2

Foul Play

Frozen Synapse

FTL: Faster Than Light

Full Mojo Rampage

Game Dev Tycoon

Garry's Mod

Gas Guzzlers Extreme

Gemini Wars

Giana Sisters: Twisted Dreams

Giana Sisters: Twisted Dreams - Rise of the Owlverlord

Go Home Dinosaurs!

God Mode

Gone Home

Goodbye Deponia

Gotham City Impostors: Free To Play

Gratuitous Space Battles

Gravi

GRID 2

Guacamelee! Gold Edition

Guardians of Middle-earth

Gun Monkeys

Guncraft

Gunpoint

Guns of Icarus Online

Hack, Slash, Loot

Half-Life 2

Hamilton's Great Adventure

Hammerwatch

Hearts of Iron III

Hitman: Absolution

Horizon

Hotline Miami

Indie Game: The Movie

Insurgency

Ion Assault

Ironclad Tactics

Ittle Dew

Jagged Alliance - Back in Action

Joe Danger

Joe Danger 2: The Movie

Journey of a Roach

Kairo

Kerbal Space Program

Killing Floor

Kinetic Void

King's Bounty: Warriors of the North

Knights of Pen and Paper +1

Knytt Underground

Krater

La-Mulana

Left 4 Dead 2

Legend of Dungeon

Lilly Looking Through

Long Live The Queen

Lords of Football

Lost Planet 3

Lunar Flight

Lunnye Devitsy

Mabinogi

MacGuffin's Curse

Magic 2014

Magical Diary

Magicka

Magicka: Wizard Wars

March of the Eagles

Mark of the Ninja

Mars: War Logs

Marvel Heroes

Master Reboot

McPixel

Medieval II: Total War

Memoria

Metal Drift

Metro: Last Light

Might & Magic: Duel of Champions

Mini Motor Racing EVO

MirrorMoon EP

Monaco

Monster Loves You!

Mount & Blade

Mount & Blade: Warband

MouseCraft

Napoleon: Total War

NASCAR The Game: 2013

Natural Selection 2

Nihilumbra

No More Room in Hell

No Time to Explain

Noitu Love 2 Devolution

Nuclear Dawn

Offspring Fling!

Omerta - City of Gangsters

Orcs Must Die! 2

Organ Trail: Director's Cut

ORION: Dino Horde

Outlast

Painkiller Hell & Damnation

Paranormal

Party of Sin

Path of Exile

PAYDAY 2

PAYDAY: The Heist

Penny Arcade's On the Rain-Slick Precipice of Darkness 4

Pinball Arcade

PixelJunk Eden

PixelJunk™ Monsters Ultimate

Port Royale 3

Portal 2

Post Apocalyptic Mayhem

POSTAL 2 Complete

Primal Carnage

Prime World

Prime World: Defenders

Prison Architect

Psychonauts

Puddle

R.I.P.D.: The Game

Ravaged Zombie Apocalypse

Reach for the Sun

Really Big Sky

Resident Evil 6 / Biohazard 6

Resident Evil Revelations / Biohazard Revelations UE

Retro City Rampage™

Retro/Grade

Retrovirus

Reus

Revenge of the Titans

RIFT™

Rise of the Triad

Rise of Venice

Risen

Risen 2 - Dark Waters

Rising Storm/Red Orchestra 2 Multiplayer

Risk of Rain

Rogue Legacy

Rome: Total War

Rush Bros

Saints Row IV

Saints Row: The Third

Sanctum 2

Satazius

Scribblenauts Unlimited

Scribblenauts Unmasked

Secret of the Magic Crystal

Sengoku

Sequence

Serious Sam 3: BFE

Shadow Warrior

Shadow Warrior Classic Redux

Shadowrun Returns

Sid Meier's Ace Patrol

Sid Meier's Civilization V

Sid Meier’s Ace Patrol: Pacific Skies

Sins of a Solar Empire: Rebellion

Skullgirls

Skulls of the Shogun

Skyward Collapse

Sleeping Dogs™

Slender: The Arrival

Smashmuck Champions

Sniper Elite: Nazi Zombie Army

Sniper Elite: Nazi Zombie Army 2

Sol Survivor

Solar Flux

Soldier Front 2

Sonic & All-Stars Racing Transformed

Space Hulk

Space Pirates and Zombies

Space Rangers HD: A War Apart

Spectraball

SpeedRunners

Spelunky

Stacking

Star Conflict

Star Wolves 3: Civil War

StarDrive

StarForge Alpha

Starpoint Gemini 2

Stealth Bastard Deluxe

Steam Summer Getaway

Stellar Impact

Storm

Street Fighter X Tekken

Strike Suit Infinity

Strike Suit Zero

Sugar Cube: Bittersweet Factory

Super House of Dead Ninjas

Super Meat Boy

Super Sanctum TD

Super Splatters

Superfrog HD

Surgeon Simulator 2013

Survivor Squad

Sword of the Stars: The Pit

Syder Arcade

System Shock 2

Tactical Intervention

Take On Mars

Tales from Space: Mutant Blobs Attack

Talisman: Digital Edition

Talisman: Prologue

Team Fortress 2

Teleglitch: Die More Edition

Terraria

Tetrobot and Co.

The Binding of Isaac

The Bridge

The Bureau: XCOM Declassified

The Chaos Engine

The Dark Eye: Chains of Satinav

The Elder Scrolls V: Skyrim

The Inner World

THE KING OF FIGHTERS XIII STEAM EDITION

The Night of the Rabbit

The Path

The Secret World

The Showdown Effect

The Swapper

The Walking Dead

The Witcher 2: Assassins of Kings Enhanced Edition

They Bleed Pixels

Titan Attacks

Toki Tori 2+

Tomb Raider

Torchlight II

Total War: ROME II

Total War: SHOGUN 2

Tower Wars

Train Simulator 2014

Trapped Dead

Trine

Trine 2

Triple Town

Tropico 4

Type:Rider

Ultratron

Unholy Heights

Universe Sandbox

Unreal Tournament 2004

Urban Trial Freestyle

Valdis Story: Abyssal City

Victoria II

Wake

Wanderlust: Rebirth

War of the Roses

War of the Vikings Early Access

Warframe

Wargame: AirLand Battle

Warlock - Master of the Arcane

Winter Voices

Worms Clan Wars

Worms Revolution

XCOM: Enemy Unknown

Zack Zero

Zeno Clash 2

Zombie Driver HD