Bloody Roar: Primal Fury

King Orion Code 
Beat survival mode fifty times, die, and then enter 
orion and go into versus mode and he will be there. 
He only can be used in versus.

Just enter:
'Q LAB' to get all upgrade.

Unlimited Missiles in driving stages
During a driving stage, pause and hold down L. Then
press 'B Y Y B Y X'. This will give you infinite missiles.

Unlock all characters in multi-player
Enter 'PARTY' into the Secret Unlocks menu.

Demolition mode
To unlock Demolition mode in multiplayer:
Enter 'TNT' into the Secret Unlocks menu.

From the Psychosis Gaming Bible

Resident Evil Zero !!NEW!!

Unlock Leech Hunter Game 
Beat the game on Easy, Normal, or Hard mode to unlock 
this mini-game.

Unlock New Costumes 
If you complete the game on Normal or Hard mode, you'll 
find the Closet Key in Rebecca's Inventory when you 
start a new game. 

Billy will get a suit and Rebecca will get a leather 
outfit or a cowgirl uniform.

From Psychosis Gaming Bible

Free Bomb Spores:
Find a full grown Bomb Spore shoot it with the staff's
fire power-up to get three Bomb Spore Seeds.

Ice Mountain: Race:
If you are having trouble winning in the race, you can
do one of two things. Either try to knock them off their
bikes or jump any hill you can that helps take the lead.

Moon Mountain Pass:(Staff ground quake upgrade:)
There will be a rock that you can flip. The upgrade is
under the rock.

Attack combos:
Hold 'Down + A' and when your staff starts to light up,
hold 'A' to get a strong attack combo.

Tricky on fire:
If you go near a fire with Tricky, he will catch on fire.

From Games Domain

Timesplitters 2

Unlock Multiplayer Maps 

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

Beat the game on 'normal' difficulty to unlock the cheat 
'all characters cloaked'

Play As Beetleman 
Get a Gold or Platinum on Double Bill on arcade mode 

Play as Stone Golem
Beat the Aztec Ruins level  

Unlock Colonel in Arcade Mode
Successfully complete the Wild West level to unlock

From Games Domain