Here is the full list of trophies you can collect that is on the trophy list in the game.
Cagefighter – Kill 10 Helghast using Brutal Melee (Bronze) – Killed 10 Helaghast using Brutal Melee
Close Quarters Killer – Kill 25 Helghast using Brutal Melee (Silver) – Killed 25 Helghast using Brutal Melee
Eagle Eye – Every Sniper Rifle bullet is a kill (Bronze) – Shot and killed 6 Helghast using the Sniper Rifle without reloading or switching weapons
Evening The Odds – Kill 500 Helghast (Bronze) – Kill 500 Helghast
Fight To The Last – Kill 1500 Helghast (Silver) – Killed 1,500 Helghast
Frag Out – Kill 3 Helghast with 1 Frag Grenade (Bronze) – Killed 3 Helghast using 1 fragmentation grenade
Grand Slam – Win a match in 3 multiplayer modes (Gold) – Won a match in Operations, Warzone & Guerrilla Warfare modes
Hand To Hand Master – Kill 50 Helghast using Brutal Melee (Silver) – Killed 50 Helghast using Brutal Melee
Handy Man – Repair an object (Bronze) – Repaired an object for the first time
In Your Face – First Brutal Melee (Bronze) – Performed first Brutal Melee move
Medic! – Revive another player (Bronze) – Revived a friendly player for the first time
Minigunned – Destroy all targets (Bronze) – Destroyed everything while using the Minigun on the Intruder
Mopping Up – Kill 40 Helghast foot soldiers (Bronze) – Killed 40 or more Helghast foot soldiers on the beach
No Witnesses – Destroy all dropships on the Highway (Bronze) – Destroy all dropships on the Highway
Now It’s Personal – Kill 1000 Helghast (Silver) – Killed 1,000 Helghast
Now You See Me – Kill using Cloak (Bronze) – Killed another player while cloaked
One Each – Kill 3 Helghast with Shotgun Pistol, no reloads (Bronze) – Shot and killed 3 Helghast using the Shotgun Pistol without reloading or switching weapons
Pinpoint – Kill the Heavy with an StA-14 (Bronze) – Killed the HEavy using the StA-14 rifle
Platinum (Platinum) – Collect all Killzone 3 trophies
Power Spike – Nail a Helghast to an exploding object (Bronze) – Used the Boltgun to nail a Helghast to an exploding object
Quick Exit – Escape the Oil Rig quickly (Bronze) – Got off the 2nd rig within 2 minutes
Ready For Battle – Complete weapons training (Bronze) – Completed weapons training in Prologue
Sawn Off – Destroy all chasing APC’s (Bronze) – Destroyed all chasing SawBlade APC’s in the Senlin Beach section
Shattered – Destroy all glass in the Labs (Bronze) – Destroy all glass panes in the Stahl Arms South laboratories
Smoking Wrecks – Destroy all Tanks on Senlin Beach (Bronze) – Destroyed all the Helghast Tanks in the Senlin Beach section
Spiky Personality – Kill a Helghast using a Burster (Bronze) – Killed a Helghast by shooting a Burster plant
Spy Game – Kill using Disguise (Bronze) – Killed another player while disguised
Team Player – Play a match as part of a squad (Bronze) – Joined and completed a match as part of a squad
Turf War – Capture a Tactical Spawn Point (Bronze) – Captured a Tactical Spawn Point for the first time
Turn The Tables – Melee Kill a Capture Trooper (Bronze) – Killed a Capture Trooper using melee
Up Close & Personal – Brutal Melee another player (Bronze) – Used the Brutal Melee move against another player
Victory – Complete Campaign on Elite (Gold) – Completed every mission on Elite difficulty
And here is the list of hidden trophies you can collect that don’t show up on the main list until you unlock them.
Aerial Superiority – Kill 5 Helghast while in the air (Bronze) – Killed 5 Helghast while airborne using the Jetpack
Bring It Down – Defeat the MAWLR (Bronze) – Defeated the MAWLR defending the Space Elevator
Completist – Destroy everything on the MAWLR (Bronze) – Destroyed every destructible weapon on the MAWLR while on foot and on the Intruder
Double Trouble – Reach the river in Co-op (Bronze) – Made it to the Corinth River in Co-op mode
Excessive Force – Kill a lone Helghast with the WASP secondary fire (Bronze) – Used the secondary fire function of the WASP launcher to kill a single Helghast
Frazzle Dazzle – Kill 3 Helghast with one shot from the StA5X Arc Cannon (Bronze) – Used the StA5X Arc Cannon to kill 3 Helghast with one shot
Go Down And Stay Down – Destroy the ATAC (Bronze) – Defeated the ATAC outside the Stahl Arms facility
Iced – Destroy all Ice-Saws and Dropships (Bronze) – Destroyed all 4 Helghast Ice-Saws and all 6 Dropships
Into The Lair – Reach the cable car (Bronze) – Reached the cable car and gained access to Stahl Arms South
Iron Man – Get a kill with the Exo (Bronze) – Killed a player using the Exo in any multiplayer mode
ISA TV – Establish communications (Bronze) – Made contact with Earth
Jail Break – Liberate Narville (Bronze) – Liberated Narville from Stahl Arms South
Let’s Go Home – Destroy Stahl’s Cruiser (Gold) – Destroyed Stahl’s Cruiser and left the planet on any difficulty
Never There – Sneak past Helghast (Bronze) – Sneaked past all Helghast in the Jungle without alerting any of them
Pilot’s Wings – Mid-air kill (Bronze) – Got a mid-air kill using the Jet Pack in any multiplayer mode
Save The Intruders – Arc APCs destroyed (Bronze) – Successfully assisted with defeating the Arc APCs
Spread The Love – Kill 5 Helghast at once using the WASP’s secondary fire (Bronze) – Killed 5 Helghast at once using the secondary fire mode of the WASP launcher
Stranded Together – Reach the Extraction Point in Co-op (Bronze) – Made it to the Extraction Point in Co-op mode
Time For A Dip – Reach the river (Bronze) – Reached the Corinth River with the convoy
You Drive – Drive the Mobile Factory (Bronze) – Took over the controls of the Mobile Factory