Arcade Adios Amigos level rewards
Successfully complete the level ''Adios Animgos'' in the arcade mode with a Gold rank to unlock Hector Babasco and Lean Molly as playable characters in arcade mode.

AstroLander Mini-Game
In the Neo Tokyo level, check the far right locker in the room with the police computer to find the ''AstroLander Cart'' you can play this mini-game by pushing Y(reload) with the Temporal Uplink equip,

Challenge Brick Rewards
Successfully complete the challenge ''Brick'' with a Gold rank to unlock the Brick weapon in Multiplayer.

Challenge Pane In The Neck level rewards
Successfully complete the challenge ''Pane In The Neck'' with a Silver rank to unlock the Rotating Heads cheat.

Ending Bonuses
Complete the entire game, successfully, under the Easy difficulty setting to unlock Cardboard Characters cheat and the Streets Multiplayer level in the Arcade mode.

Female Trooper
Defeat Amateur League / It's a Blast / Demolition Derby with a Gold medal or better.

Infinite Ammo
Complete Story Mode on the Hard difficulty setting to unlock infinite ammunition in all game modes.

Play as Ample Sally
Defeat Elite Challenge / Cut-out Shoot-out / Take 'Em Down with a Silver medal or better.

Play as Aztec Warrior
Defeat Elite League / Duel Meaning / Golden Thighs with a Silver medal or higher.

Play as Baby Drone
Defeat Elite League / Team Series C / They're Not Pets! with a Silver medal or better.

Play as Barby Gimp
Defeat Honorary League / Outnumbered But Never Outpunned / Time to Split with a Silver medal or better.

Play as Beetleman
Defeat Elite League / One Shot Thrills / Double Bill with a Silver medal or higher.

Play As Braces
Defeat Honorary League / Elimination Series / Men In Grey with a Gold medal or better.

Play As Braces
Defeat Honorary League / Elimination Series / Men In Grey with a Gold medal or better.

Play as Changeling
Defeat Elite League / Frantic Series / Can't Please Everyone... with a Silver medal or higher.

Play as ChassisBot
Defeat Arcade League / Mode Madness / Scrap Metal with a Gold medal or better.

Play As Crispin
Defeat Amateur League / Too Hot to Handle / Monkey Immolation with a Gold medal or better.

Play as Crypt Zombie
Defeat Arcade League / Beginners Series / Casualty with a Gold medal or better.

Play as Cyberfairy
Defeat Elite League / Frantic Series / Hangar Hat's On! with a Silver medal or better.

Play as Dark Henchman
Defeat Elite League / Frantic Series / Hangar Hat's Off with a Gold medal or higher.

Play as Dr. Peabody
Defeat Arcade League / Beginners Series / Casualty with a Silver medal or better.

Play as Duckman Drake
Defeat Challenge / Outnumbered But Never Outpunned / Someone Has Got to Pay... with a Silver medal or higher

Play as Feeder Zombie
Defeat Challenge / Behead the Undead / Day of the Damned with a Silver medal or better.

Play as Gargoyle
Defeat Honorary League / Maximus / Cold Corpse Caper with a Silver medal or higher.

Play as Hatchet Sal
Defeat Honorary League / Outnumbered but Never Outpunned / Can't Handle This with a Silver medal or higher.

Play as Hector Baboso
Defeat Arcade League / Beginners Series / Adios Amigos with a Silver medal or better.

Play as Henchman
Defeat Elite League / Frantic Series / Hangar Hat's On! with a Silver medal or better.

Play as High Priest
Defeat Elite League / Duel Meaning / Golden Thighs with a Gold medal or higher.

Play as Jebediah Crump
Defeat Elite League / Sincerest Form of Flattery / Dead Fraction with a Silver medal or better.

Play As Jimmy Needles
Defeat Amateur League / Team Series A / Club Soda with a Gold medal or better.

Play as Jinki
Defeat Elite League / One Shot Thrills / Nikki Jinki Bricky with a Gold medal or better.

Play as Jo-Beth Casey
Defeat Elite League / One Shot Thrills / Babes in the Wood with a Silver medal or better.

Play as Krayola
Defeat Honorary League / Team Series B / Hack A Hacker with a Gold medal or higher.

Play as Krayola
Defeat Honorary League / Team Series B / Hack A Hacker with a Gold medal or higher.

Play as Krayola
Defeat Honorary League / Team Series B / Hack A Hacker with a Gold medal or higher.

Play as Krayola
Defeat Honorary League / Team Series B / Hack A Hacker with a Gold medal or higher.

Play as Krayola
Defeat Honorary League / Team Series B / Hack A Hacker with a Gold medal or higher.

Play as Kypriss
Defeat Elite League / Duel Meaning / Golem Goru with a Silver medal or better.

Play as Lean Molly
Defeat Arcade League / Beginners Series / Adios Amigos with a Gold medal or better.

Play as Lola Varuska
Defeat Challenge / Monkeying Around / Monkey Mayhem with a Gold medal or better.

Play As Louie Bignose
Defeat Amateur League / Too Hot to Handle / Disco Inferno with a Silver medal or better.

Play as Maiden
Defeat Elite League / Frantic Series / Can't Please Everyone with a Silver medal or better.

Play as Male Trooper
Defeat Amateur League / It's a Blast / Demolition Derby with a Silver medal or higher.

Play as Marco the Snitch
Defeat Challenge / Cut-out Shoot-out / Fall Out with a Silver medal or better.

Play as Meezor Mox
Defeat Amateur League / It's a Blast / Spoils of War with a Gold medal or better.

Play as Mikey Two-Guns and Jared Slim
Defeat Elite League / Duel Meaning / If I'm Ugly - You Smell! with a Silver medal or better.

Play as Mister Giggles
Defeat Elite League / Frantic Series / Big Top Blowout with a Silver medal or better.

Play as Nikki
Defeat Elite League / One Shot Thrills / Nikki Jinki Bricky with a Silver medal or better.

Play as R One-Oh-Seven
Defeat Challenge / TimeSplitters 'Story' Classic / But Where Do the Batteries Go? with a Silver medal or better.

Play as Ringmistress
Defeat Elite League / Teams Series C / Bags of Fun with a Gold medal or better.

Play as Riot Officer
Defeat Honorary League / Team Series B / Rice Cracker Rush with a Silver medal or better.

Play as Scourge Splitter
Defeat Honorary League / Outnumbered But Never Outpunned / Time to Split with a Gold medal or better.

Play as SentryBot
Defeat Amateur League / It's a Blast / Night Shift with a Gold medal or better.

Play as Sewer Zombie
Defeat Challenge / Behead the Undead / Fight Off the Living Dead with a Silver medal or higher.
Play As Slick Tommy
Defeat Amateur League / Team Series A / Club Soda with a Silver medal or better.

Play as Strumpy
Defeat Elite League / Frantic Series / Big Top Blowout with a Gold medal or better.

Play As The Accountant and The Lawyer
Defeat Amateur League / Team Series A / Men In Grey with a Gold medal or better.

Play as The Cropolite
Defeat Challenge / TimeSplitters 'Story' Classic / Hit Me Baby One Morgue Time with a Silver medal or higher.

Play as The Hunchback
Defeat Challenge / Glass Smash / Stain Removal with a Silver medal or higher.

Play as The Master
Defeat Honorary League / Team Series B / Rice Cracker Rush with a Gold medal or higher.

Play As Undead Priest
Defeat Amateur League / Too Hot to Handle / Burns Deparetment with a Gold medal or better.

Play as Venus Starr
Defeat Honorary League / Burns 'n' Bangs / Rocket Man with a Silver medal or better.

Play as Wood Golem
Defeat Challenge / Banana Chomp / Playing with Fire with a Silver medal or higher.

Secret "Anaconda" Cart
In the 1990 Siberia level, on a shelf inside the main facility on the western side of the dam, a game cartridge labelled ''Anaconda'' can be found.

By selecting the Temporal Uplink and pressing the reload button, you can play the game on the cartridge, which is loosely based around Snake, found on most Nokia cell-phones.

***Note: press left and right to ''steer'' your snake, and press the action button to give it a speed boost.

Secret AstroLander Game
When playing on the Normal or Hard difficulty settings, another cartridge can be found on the 2019 NeoTokyo level, inside the locker room in the research facility. (It's in the locker on the left).

By selecting the Temporal Uplink and pressing the reload button, you can play the game on the cartridge, which is based upon Lunar Lander, a classic Atari coin-op game.

Secret RetroRacer Game
When playing on the Hard difficulty setting only, a final cartridge can be found on the 2315 Robot Factory level, in the huge bunker with armor placed beneath one of the ramps. Underneath the other ramp is the RetroRacer cartridge.

By selecting the Temporal Uplink and pressing the reload button, you can play the game on the cartridge, which is a top-down racer, similar to Micro Machines or Sprint 2.

Unlock "The Site" level
To unlock ''The Site'' level in multi-player, simply beat the game under the hard difficulty setting.

Unlock Milkbaby
Defeat Honorary League / Team Series B / Hack a Hacker with a Silver medal or higher

Unlock Multiplayer Maps
Mexican Mission: Available by Default

Ice Station: Available by Default

Hospital: Available by Default

Training Ground: Available by Default

Aztec: Available by Default

Scrapyard: Clear Arcade League - Amateur League - Mode Madness - Scrap Medal with a Bronze Medal or higher

Nightclub: Clear Arcade League - Amateur League - Too Hot to Handle - Disco Inferno with a Broze Medal or higher

Hangar: Clear Arcade League - Amateur League - Beginner's Series - Top Shot with a Bronze Medal or higher

Robot Factory: Clear Arcade League - Amateur League - It's a Blast - Demolition Derby with a Bronze Medal or higher

Ufopia: Clear Arcade League - Honorary League - Maximus - Cold Corpse Caper with a Bronze Medal or higher

Chinese: Clear Arcade League - Honorary Leauge - Elimination Series - Starship Whoopers with a Bronze Medal or higher

Chasm: Clear Arcade League - Honorary League - Outnumbered but Never Outpunned - Can't Handle This with a Bronze Madal or Higher

Streets: Clear Spaceship: 2401 on the Easy difficulty setting

Compund: Clear Spaceship: 2401 on the Normal difficulty setting

Site: Unknown, Probably linked to amount of Arcade League matches or Challenges completed

Circus: Clear Challenge - Monkeying Around - Dam Bursters with a Bronze Medal or higher
Contributed By: bluberry, Source: Self, Friend
Unlock Snowman Character
Defeat Honorary League / Burns 'n' Bangs / Snow Business with a Silver Medal or Higher.
Contributed By: Guitarfreak86, Source: Self
Unlockable Characters through Single Player
Note that the levels must be completed on Normal or higher to get the character.

Clear 1990 Siberia to get Hybrid Mutant
Clear 1932 Chicago to get Big Tony
Clear 1895 Notre Dame to get Jacque de la Morte
Clear 2280 Return to Planet X to unlock Ozor Moxx
Clear 2019 NeoTokyo to unlock Sadako
Clear 1853 Wild West to unlock The Colonel
Clear 1972 Atom Smasher to unlock Khallos
Clear 1920 Aztec Ruins to unlock Stone Golem
Clear 2315 Robot Factory to unlock Machinist
Clear 2401 SpaceStation to unlock Berserker Splitter