Edit the file AUTOEXEC.CFG (found in Kingpin's ''Main'' directory) and add the following line:
set developer 1

You may now enter the following codes by pressing the single quote (`) key while playing and typing the desired code in the console window.
Code                    Effect
give cash               100 Dollars
give weapons            all weapons
give all                all weapons, ammo and health
give armor              full armor
give health             full health
immortal                immortality
give (item)             special item
noclip                  walk through walls
give (weapon)           weapon


Level Selection

Enable the console by using this command to create a shortcut : c:\kingpin\kingpin.exe +developer 1. Run the game from this shortcut. Once in the game, press the ~ key and type these commands to automatically go to these levels.
Code                    Effect
map bike                Bike
map pv_b                Blanco Industries
map bar_st              Boiler Room
map bar_rv              Club Swank
map sy2                 Das Boot
map bar_sr              Jax
map sy_h                Lizzie's Problem
map pv_1                Louie's Errand
map sr3                 Mean Streets
map steel4              Moker Shipping
map pv_boss             Nikki Blanco
map sy1                 Pier Pressure
map pv_h                Poisonville
map bar_sy              Salty Dog
map sewer               Sewers
map sr1                 Skidrow
map steel2              Steel Mill
map steel3              Steel Processing
map steel1              Steeltown
map sr2                 Super
map sr4                 The Jesus


Secrets
Secret Weapon in Demo

The secret weapon in the Kingpin demo, which was mentioned in the readme file, is the flamethrower! To get the flamethrower, go to the place with the old car in the map SR3. After you killed the dogs and picked up the battery, jump onto the roof of the car and shoot it. Then bang on or shoot the bottom until it breaks, revealing a box. DON'T SHOOT IT! Instead, bang on it with the crowbar or lead pipe to pick up the flamethrower. Now that you have it, go NUTS! But be warned: there's only 50 flamethrower ammo to be found.