Dead Nation Cheats - PlayStation 3

Unlock Trophies
Aim For The Head (Silver) - Perform 500 Headshots.
A Trip Downtown (Bronze) - Complete Mission 2 (any difficulty level).
And So It Begins... (Bronze) - Complete Mission 1 (any difficulty level).
Blown To Bits (Bronze) - Blow Up 1,000 Zombies.
Easy Does It (Bronze) - Complete Campaign Mode on 'Braindead'.
Genocidiary (Gold) - Kill 53,596 Zombies.
Gravedigger (Bronze) - Complete Mission 7 (any difficulty level).
Car Killer (Bronze) - Destroy 500 Vehicles.
Contributor (Bronze) - Help Your Country To Clear The Virus Infection.
Double the Action (Gold) - Complete Campaign Mode in Co-Op Mode.
Hospital Bill Through the Roof (Bronze) - Complete Mission 6 (any difficulty level).
King Of Looters (Gold) - Collect All The Loot In Every Mission.
Romero Would Be Proud (Platinum) - Collect All Trophies.
Skilled (Silver) - Complete A Mission Without Receiving Any Damage.
Sleeping with the Fishes (Bronze) - Complete Mission 9 (any difficulty level).
Suit Up (Bronze) - Collect An Armor Piece.
Looter (Silver) - Collect All The Loot In Any Mission.
Mediocrity (Silver) - Complete Campaign Mode On 'Normal'.
Morbid Curiosity (Gold) - Complete Campaign Mode On 'Morbid'.
On top of the World (Bronze) - Complete Mission 4 (any difficulty level).
Out of the City (Bronze) - Complete Mission 5 (any difficulty level).
Pyromaniac (Bronze) - Burn 1,000 Zombies.
Survivor (Bronze) - Complete A Mission Without Dying.
Teamwork (Bronze) - Complete A Mission in Co-Op Mode (any difficulty level).
Took the Highway (Bronze) - Complete Mission 10 (any difficulty level).
Top Gear (Gold) - Collect All Armor Pieces.
Tough Enough (Silver) - Complete Campaign Mode On 'Grim'.
Train to Nowhere (Bronze) - Complete Mission 8 (any difficulty level).
Up Close & Personal (Bronze) - Perform 500 Melee Kills.
Upgrader (Bronze) - Fully Upgrade A Single Slot Of Any Weapon In Campaign Mode.
Very Dead (Silver) - Complete A Mission On 'Undead'.
Walk in the Park (Bronze) - Complete Mission 3 (any difficulty level).
Weapons Specialist (Silver) - Fully Upgrade All Slots Of Any Weapon In Campaign Mode.
Zombie Hunter (Silver) - Kill 10,000 Zombies.
Zombie Killer (Bronze) - Kill 1,000 Zombies.

Additionally, there are six Road of Devastation DLC trophies:

Combo Master (Silver) - Get the Apocalypse Combo Kill Bonus (150 Kills).
Keep It Up (Silver) - Complete a Round with a Kills-per-minute ratio of 100 or more.
Dynamic Duo (Bronze) - Complete a Round in Co-Op Without Either Player Taking Damage.
Found 'Em (Bronze) - Find all the Egogate emblems.
Never Give Up (Gold) - Survive to Round 10.
Still In the Game (Bronze) - Survive to Round 5.

Last Checkpoint of the Graveyard
There are 4 Mouths in this area who scream and summon infinite enemies to attack you. If you don't kill most of the enemies in the previous area (before the checkpoint) there will be too many enemies on screen and when the Mouths scream no extra enemies will be summoned. This makes it much easier to beat this area on Grim and Morbid difficulties.