Super Cop mode:
Successfully complete story mode under the normal difficulty setting.No damage mode:
Successfully complete the Roof Tops level in Super Cop mode.
Infinite ammo:
Successfully complete the Groove level in Super Cop mode.
Infinite adrenaline:
Successfully complete the Back Streets level in Super Cop mode.
Incredibly fit dog mode:
Successfully complete the Under Rink level in Super Cop mode. This mode results in unlimited Shadow attacks.
Superdeform mode:
Successfully complete the Pink Starfish level in Super Cop mode. This mode results in big head, feet, and hands.
Challenge mode:
Successfully complete story mode under the normal difficulty setting to unlock challenge mode with normal difficulty.
Fists Of Flame mode:
Successfully complete the Abattoir level in Super Cop mode.
Multi-player skins and levels:
Successfully complete story mode under the normal difficulty setting. You will unlock a new skin or level for each level completed.
Cabal Boss multi-player skin:
Successfully complete the Dock Yard level in Super Cop mode.
Maxine multi-player skin:
Successfully complete the Manson level in Super Cop mode.
Unlock Everything:
Enter your name as DoggieStyle (case sensitive) to unlock everything.
Unlock Supercop and Challenge mode:
Normal Challenge mode - Beat game in Normal
Supercop mode (hard difficulty) - Beat game in Normal
Unlockable How to Unlock:
Incredible Fit Dog - complete stage 6
Infinite Adrenaline - complete stage 5
Infinite ammos - complete stage 4
Super Deformed Mode - complete stage 2
Unlockables Bonuses:
Complete these chapters on Rookie/Normal to unlock the bonuses.
Unlockable Level:
Bar (Multiplayer Arena) Chapter 02
Biker 2 (Multiplayer Skin) Chapter 01
Biker Boss (Skin) Chapter 03
Cabal1 (Skin) Chapter 09
Cabal2 (Skin) Chapter 10
Jack2 (Skin) Chapter 05
Mansion (Arena) Chapter 11
Militia Boss (Skin) Chapter 08
Militia2 (Skin) Chapter 07
Triad Boss (Skin) Chapter 06
Triad2 (Skin) Chapter 04
Whisper (Skin) Chapter 12
Play Multiplayer with one disc:
It's simple. First, the host must create a game. Choose all the settings, etc, and actually start the game. Then, pop out the UMD, and give it to a friend. Your friend simply loads up the game on his PSP, and then joins your game. This can work with several people in the same manner. However, setting the frag limit high is a good idea, because once the game is over, you have to redo the whole process, because the game needs to load again, and cannot without a UMD.