Grand Theft Auto III

When not going through a normal mission, get in an Ambulance and press R3.

Save 35 pedestrians and a health refill will appear outside any of your save points.

Save 70 pedestrians and an adrenaline pill will appear outside any of your save points.

Complete the Ambulance level 12 and Infinite Run will be granted.

NOTE:You do not have to save the pedestrians consecutively. You can do it as you go through the game.

Just set your console and the game language to English, this allows you to play the game without censorship.
Now you can also hit opponents while they are on the ground, a feature that was removed from the German version.

For these codes to work, enter them during normal gameplay, whilst in any city.(Note: The speed up and slow down codes can be used multiple times to make the game even slower or faster.)

After you pay to repair your car in the Pay 'N Spray, drive back in and you can get a free paint job.

Get into a car. Drive in front of the desired car (to keep it front driving away) that you would like to drive after it's been blown up. THE CAR MUST HAVE SOMEONE IN IT. Walk up to the driver's side door. Enter the ''Blow up all cars'' code. While entering the code, Mr. GTA (or whatever his name is) will pull the driver out of the car and then get into it as it's blowing up and somehow he will not die. But as soon as you are in the car, enter the Health Code to extinguish the flame. It might not work the first time, so keep trying and eventually it will work.

Whenever you want to drive without the threat of traffic, just change the camera to be in the top-down view! Traffic will not spawn (save for police vehicles when you're wanted), allowing you to drive unimpeded.

Start a Vigilante mission. Once you get near the suspect's car. Hit pause, and then un-pause it. The suspect will jump out of the car for no reason. Now you can run them over.

While not doing a normal mission, get in a Fire Truck and press R3. There is a Fire Station on each island. Put out 20 fires on each island and a Flame-thrower will always appear at one of your three save points.

NOTE: The fire missions do not have to be done consecutively. Just make sure you have put out 20 fires in each area.

Near the Traid Gang area, there is a subway entrance that is blocked off. It has stairs leading down to it. There is a ramp that causes you to fly over the small gap. But if you drive up very slowly then you will fall of the ramp and land on the stairs. If you done this correctly then you should go through the cage. You will now be in the subway. You will now be able to either take a train to another island or drive your car to another island through the subway. This glitch works well with a Police car or a Taxi.

At the first island drive your car towards the tunnel that blocks off the third and second island. Park the car right next to the blue wall and blow it up. You should be blown through into the third or second island.