Mission Achievement
These cheats will help you unlock achievements in completing missions in both Normal and Hard Difficulty. Nothing like getting an achievement for a hard difficulty while cheating, huh?
To enable the cheats, you must be in an active game. That is, start or continue a game, then press START to enter the pause menu. While the game is paused Hold LT+RT+BACK then enter the codes. A tone will be heard once you have entered the correct code.
These cheats must be re-entered after each extraction point.
CHEAT EFFECT
Y, Y, X, RB, X, LB Scott Mitchell is Invincible
X, X, Y, RB, Y, LB Team is Invincible
RB, RB, LB, X, LB, Y Infinite Ammo
LB, LB, RB, X, RB, Y Refill Health 100%
Y, RB, Y, RB, X Unlock All Missions
Multiplayer Achievements
There are a lot of Multiplayer Achievements that can be unlocked simply by using a second controller.
There was a time when you could climb to the top and be World Solo Champion by using a second controller ( sign in your second controller as a guest into Xbox Live, then win all your matches ) but sadly some spoil sport decided to update the game and take away this absolutely brilliant feature.
Anyway there are still some points that can be obtained by using a second controller.
Heavyweight (Multiplayer) 24 G
Get a total of 10,000 kills in multiplayer
This achievement sounds cool and probably quite hard doing legit. Plug in a second controller and start a co-op Objectives or co-op Territories. Set the respawns and enemy density to infinite in Advanced Options. Set the match to 60 mins. Just stick close to your base and kill them as they advance towards you.
On the Wharf Map , they spawn on the beach, so head down there with a grenade launcher and you can rack up about 10 - 15 at a time.
Deadly (Multiplayer) 20 G
Get 4 kills in 4 seconds or less in multiplayer
You should get this while going for Heavyweight Achievement. Heading down to the beach on the Wharf Map with a grenade launcher will easily unlock this. Or wait until there is a group of enemies heading towards you, them let them have it.
Unyielding (Multiplayer) 32 G
Get 30 kills before being killed in multiplayer
Another Multiplayer achievement that sounds hard, but so, so easy. Stick in another controller and start a Solo Elimination match. Set the re-spawns to infinite. Just shoot the second controller 30 times in a row. Try doing head shots, as it will help you get the "Sniper" achievement.
Once the second controller is killed, you can choose the re-spawn point using the second controller, so make sure you choose a point right next to the first controller. Otherwise you will spend a lot of time searching for the second controller.
Sniper (Multiplayer) 36 G
Get a career total of 500 head shots in multiplayer
Use the same method as "Unyielding" achievement above, except brain the second controller. This could be a little time consuming, but with the amount of kills being displayed in the right hand corner of you HUD, it 's quite easy to track. Remember it does not have to be a sniper rifle.
Falcon (Multiplayer) 16 G
Shoot down 100 helicopters in multiplayer
Set up a Territory game Hamburger Hill with a second controller. Whoever controls the hill, will have control of the helicopter. So send the second controller to run up to the hill and the then wait for the helicopter to spawn. Shoot down the helicopters using a Sniper Rifle. Rinse and repeat until you reach 100.
Committed (Multiplayer) 28 G
Play for 8 hours straight in multiplayer
Here's another achievement you can earn by being asleep! Set a Co-op Elimination game. Set 30 second auto-launch timer and infinite respawns, then set the match 60 mins. Then go to bed. When you wake up, it will pop.