Complete the indicated task to unlock the corresponding mission.
Behind the Scenes: Complete Story mode under the Normal difficulty.
Lian: Complete all five training missions.
Killing Time: Earn the Combat Knife Specialist Rating 4 career rank.
Left Behind: Earn the Elite Weapons Expert Rating 4 career rank.
Shadowed: Complete Story mode under the Hard difficulty.
Bonus weapons
Complete the indicated task to unlock the corresponding weapon in Mission mode.
C11: Earn the Combat Knife Specialist 2 career rank.
Calico HE: Earn the Survival Specialist Rating 4 career rank.
Chinese Type 56: Earn the Combat Knife Specialist Rating 3 career rank.
EPDD: Earn the Stealth Combat Specialist Rating 4 career rank.
FAMAS: Complete the Training 2 mission in under 3 minutes.
Flashbang Grenade: Earn the Combat Knife Specialist Rating 1 career rank.
Jackhammer HE: Earn the Tactical Combat Specialist Rating 4 career rank.
Jerico-41: Earn the Tactical Combat Specialist Rating 2 career rank.
M4 Silenced: Earn the Survival Specialist Rating 3 career rank.
M67 Grenade: Earn the Tactical Specialist Rating 3 career rank.
M82 BFG: Earn the Combat Sharp Shooter Rating 4 career rank.
MDS A4 Silenced: Earn the Stealth Combat Specialist Rating 2 career rank.
Over Under: Earn the Combat Sharp Shooter Rating 2 career rank.
Sawed-Off Pistol: Earn the Survival Specialist Rating 1 career rank.
Silenced .44: Earn the Stealth Combat Specialist Rating 3 career rank.
SP - 57: Complete the Training 1 mission in under 1 minute and 30 seconds.
SSP 90: Earn the Combat Sharp Shooter Rating 1 career rank.
TK-9 Silenced: Earn the Stealth Combat Specialist Rating 1 career rank.
UNP .45: Complete the Training 3 mission without missing any shots.
USAS - 12: Earn the Tactical Combat Specialist Rating 1 career rank.
Ladder Invisible Person
You go to sand war map and go to the crate over to the left side of map jump on while pressing Up and Circle. You should be able to not get on top of the crate. If you don't go to the ladder in that same area and take one step and go back down then you be invisible.
Upgrades
Earn the indicated career rank to unlock the corresponding upgrade in Mission mode.
Dual Wield: Combat Sharp Shooter Rating 3
Increased Health: Survival Specialist Rating 2
Max Darts x 10 (MB150): Elite Weapons Expert 3
Max Darts x 5 (MB150): Elite Weapons Expert 1
Max Darts x 8 (MB150): Elite Weapons Expert 2