Check out what you unlock in each of the modes:

Story Mode

• Finish Easy - Cardboard Characters Cheat, Streets
• Finish Normal - Big Heads Cheat, All Characters Cloaked Cheat, Compound
• Finish Hard - Unlimited Ammo Cheat, Site
• 1990, Siberia Normal/Hard - Mutant TimeSplitter
• 1932, Chicago Normal/Hard - Big Tony
• 1985, Notre Dame Normal/Hard - Jacque de la Morte
• 2280, Return to Planet X Normal/Hard - Ozor Mox
• 2019, NeoTokyo Normal/Hard - Sadako
• 1853, Wild West Normal/Hard - The Colonel
• 1972, Atom Smasher Normal/Hard - Khallos
• 1920, Aztec Ruins Normal/Hard - Stone Golem
• 2315, Robot Factory Normal/Hard - Machinist
• 2401, Space Station Normal/Hard - Reaper Splitter

Arcade Mode

Arcade Mode - Amateur League

• Adios Amigos! - Hector Babosa, Lean Molly
• Casualty - Dr. Peabody, Crypt Zombie
• Top Shot - Sgt. Shock, Elimination Mode
• Chastity Chased - Regeneration Mode
• Shrinking from the Cold - Private Sand, Sgt. Slate, Shrink Mode
• Scrap Metal - Scrapyard, ChassisBot
• Night Shift - Sentry Bot, Leech Mode
• Spoils of War - Meezor Mox, Thief Mode
• Demolition Derby - Male Trooper, Female Trooper, Robot Factory Level, Vampire Mode
• Monkey Immolation - Crispin, Flame Tag Mode
• Disco Inferno - Louie Big Nose, Lt. Wild
• Burns Department - Undead Priest, Nightclub, Virus Mode
• Club Soda - Slick Tommy, Jimmy Needles
• Station Stand - Lt. Shade, Zones Mode
• Men in Gray - Accountant, Lawyer, Assault Mode

Arcade Mode - Honorary

• Cold Corpse Caper - Cyber Fairy, Gargoyle
• Killer Queen - Leo Krupps
• 109 beta - Ufopia, Gladiator Mode, Roman Hat, Lt. Chill
• Baking for the Taking - Chinese Chef, Gingerbread Man
• Brace Yourself - Braces, Trooper Brown
• Starship Whoopers - Chinese, Monkey Assistant Mode, Trooper Black
• Chinese Burns - Calamari, Chef Hat
• Snow Business - Snowman, Trooper Grey
• Rocket Man - Venus Star, Capt. Sand, Duckman Drake
• Someone Has Got to Pay... - Capt. Night
• Time to Split - Barby Gimp, Scourge Splitter
• Can't Handle This - Chasm, Hatchet Sal, Handyman
• Hack a Hacker - Krayola, Milkbaby
• Rice Cracker Rush - Riot Officer, the Master
• Superfly Lady - Capt. Pain

Arcade Mode - Elite League

• Babes in the Woods - Jo-Beth Casey
• Double Bill - Beetleman, the Impersonator
• Nikki Jinky Bricky - Nikki, Jinki
• If I'm Ugly, You Smell! - Mikey Twoguns, Jared Slim
• Golem Guru - Kypriss, Fat Characters Cheat
• Golden Thighs - High Priest, Aztec Warrior
• Hangar Hats Off! - Henchman, Dark Henchman
• Can't Please Everyone... - Maiden, Changeling
• Big Top Blowout - Mr. Giggles, Stumpy
• Bags of Fun - Ringmistress, Big Hands Cheat, Slow Motion Deads Cheat
• They're Not Pets! - Baby Drone, Bear
• Nice Threads - Small Heads
• Aztec the Dino Hunter - Dinosaur
• Half Death - Drone Splitter
• Dead Fraction - Jebediah Crump

Challenge Mode

Glass Smash

• Pane In the Neck - Rotating Heads Cheat
• Bricking It - Brick (Weapon)
• Stain Removal - Hunchback

Behead the Undead

• Fight Off the Living Dead - Sewer Zombie
• Sergio's Last Stand - Sergio
• Day of the Damned - Feeder Zombie

Infiltration

• Silent, But Deadly - Viking Hat
• Trouble at the Docks - Pirate Hat
• Escape From NeoTokyo - Big Ears Hat

Banana Chomp

• Gone Bananas - Private Coal
• Monkey Business - Private Poorly
• Playing With Fire - Wood Golem

Cut-Out Shoot-Out

• Take 'em Down - Ample Sally
• Fall Out - Marco the Snitch
• Pick Yer Piece - Sgt. Rock

TimeSplitters "Story" Classic

• Badass Buspass Impasse - Badass Cyborg
• But Where Do the Batteries Go? - R One-Oh-Seven
• Hit Me Baby One Morgue Time - Cropolite

Monkeying Around

• Simian Shootout - Insect Mutant
• Monkey Mayhem - Lola Varuska, Mischief
• Dam Bursters - Robofish, Circus