Health Boost (Call Carmen and select 'Health Boost'):
Get 80% Relationship Status with Carmen.

Remove Up to 3 Wanted Stars (Call Kiki and select 'Remove Wanted'):
Get 80% Relationship Status with Kiki.

50% off for ALL Clothing Stores:
Get 80% Relationship Status with Alex.

Free Ride (Call for a Taxi):
Gain 60% friendship with Roman.

Discount Guns (Buy weapons at a cheaper price from Lil Jacob):
Gain 60% friendship with Little Jacob.

Extra Help (Gang members arrive in a car to help you out):
Gain 60% friendship with Dwayne.

Chopper Ride (Call Bruce to pick you up in his helicopter):
Gain 70% Friendship with Brucie.

Boom? (Call Packie for him to make you a car bomb):
Gain 75% friendship with Packie.
When you complete the following tasks you will be rewarded with the corresponding Trophy. There are 51 trophies in total.

Bronze - Assassin's Greed:
Completed ALL 9 Assassin missions.

Bronze - Auf Wiedersehen Petrovic:
Win in ALL variations of Multiplayer games.

Bronze - Chain Reaction:
Explode 10 vehicles in 10 seconds.

Bronze - Cleaned The Mean Streets:
Catch 20 criminals through the police computer.

Bronze - Courier Service:
Complete ALL 10 package delivery jobs.

Bronze - Cut Your Teeth:
Successfully promoted up a rank in Multiplayer.

Bronze - Finish Him:
Completed 10 melee counters in 4 minutes.

Bronze - Fly The Co-op:
Completed 'Deal Breaker', 'Hangman's Noose' and 'Bomb the Base II' in time.

Bronze - Full Exploration:
Unlock ALL the islands.

Bronze - Genetically Superior:
Come 1st in 20 Single-Player street races.

Bronze - Gobble Gobble:
Get a turkey in 10-pin bowling.

Bronze - Half Million:
Amass a fortune of $500,000.

Bronze - It'll Cost Ya:
Make a taxi trip from one island to another without skipping.

Bronze - Join The Midnight Club:
Win a Multiplayer race without damaging your vehicle too much.

Bronze - King of QUB3D:
Beat the high score in QUB3D.

Bronze - Let Sleeping Rockstars Lie:
Kill a Rockstar in Multiplayer.

Bronze - Manhunt:
Complete the most wanted side mission.

Bronze - Off The Boat:
Complete the first mission.

Bronze - One Hundred And Eighty:
Score 180 with 3 darts.

Bronze - Order Fulfilled:
Complete ALL 10 Exotic Export orders.

Bronze - Pool Shark:
Beat a friend at pool.

Bronze - Rolled Over:
Manage 5 car rolls in a row from one crash.

Bronze - Sightseer:
Take ALL variations of the helicopter tours of Liberty City.

Bronze - Taking It For The Team:
You were on the winning team in ALL Multiplayer team games.

Bronze - Teamplayer:
Kill 5 opposing team members.

Bronze - Top Of The Food Chain:
Successfully kill 20 players with a pistol in a Deathmatch.

Bronze - Top The Midnight Club:
Win 20 different Multiplayer standard races.

Bronze - Under The Radar:
Flew under ALL the main bridges in the game.

Bronze - Walk Free:
Successfully lost a 4 star wanted rating.

Bronze - Warm Coffee:
You were invited into your girlfriend's house.

Bronze - Wheelie Rider:
Complete a 500 foot wheelie on a motorbike.

Bronze - You Got The Message:
Deliver ALL 30 cars ordered through text message.

Silver - Dare Devil:
Complete ALL the unique stunt jumps.

Silver - Endangered Species:
Collect every hidden package in the game.

Silver - Liberty City (5):
Your friends ALL like you above 90%.

Silver - One Man Army:
Survive a 6 star wanted level for a full 5 minutes.

Gold - Key To The City:
Complete GTA IV to 100%.

Gold - Liberty City Minute:
Finish the story in less than 30 hours.

Gold - Wanted:
Achieve the highest personal rank possible in Multiplayer.


Secret Trophies

Bronze - Dial B For Bomb:
Unlock the special ability of Packie's car bomb placement.

Bronze - Driving Mr. Bellic:
Unlock the special ability of Roman's taxi.

Bronze - Fed The Fish:
Complete the mission 'Uncle Vlad'.

Bronze - Gracefully Taken:
Complete the mission 'I'll Take Her'.

Bronze - Impossible Trinity:
Complete the mission 'Museum Piece'.

Bronze - Lowest Point:
Complete the mission 'Roman's Sorrow'.

Bronze - No More Strangers:
Meet ALL the random characters.

Bronze - Retail Therapy:
Unlock the special ability of buying guns from Little Jacob.

Bronze - That Special Someone:
Complete the mission 'That Special Someone'.

Bronze - That's How We Roll!:
Unlock the special ability of Brucie's helicopter ride.

Silver - You Won!:
Complete the story.

Silver - Taking A Liberty:
Sorry for taking liberties with your time.
To be able to get 100% completion of the game the following list must be completed.

Complete ALL 90 story and procedural missions to get 68% complete.

Complete ALL 30 car thefts to get an additional 2%.

Complete ALL 50 stunt jumps to get an additional 2.5%.

Complete ALL 20 vigilante crimes to get an additional 2.5%.

Kill ALL 30 people on the list to get an additional 2.5%.

Collect ALL 200 pigeons (flying rats) to get an additional 2.5%.

Beat friends or computers at every activity to get an additional 5%.

Find ALL random characters and complete their missions to get an additional 5%.

Excluding Roman or Dwayne get ALL your friend's special abilities and do ALL their activities to get an additional 10%.
In GTA IV cheats are activated via using the mobile phone. Try entering any of the following codes after Roman has given you his old mobile phone. This happens pretty early in the game so you don't have to wait long before you can enter the cheat codes. Once you have the phone you can enter them as often as you like.

Okay, first get out your mobile phone and press x to raise the phone higher and reveal the complete keypad then use your controller to select the set of numbers according to which cheat you want to use, after you have entered the code the cursor moves to the dial button, just press x again and if successful you will see a message 'Cheat Activated' on the screen.

It's still early days for these cheat codes, so we advise you not to save your game after you have enabled a cheat code.

Full health
Call 3625550100

Full health and ammunition
Call 4825550100

Reset wanted level
Call 2675550100

Wanted level up one
Call 2675550150

Weapons 1
Call 4865550100

Weapons 2
Call 4865550150

Change weather and brightness
Call 4685550100

Spawn Annihilator cop helicopter
Call 3595550100

Spawn Cognoscenti
Call 2275550142

Spawn Comet
Call 2275550175

Spawn FBI Buffalo
Call 2275550100

Spawn Jetmax
Call 9385550100

Spawn NRG-900
Call 6255550100

Spawn Sanchez
Call 6255550150

Spawn SuperGT
Call 2275550168

Spawn Turismo
Call 2275550147