Unlockables brought to you by 
Unlockable Charaters
complete Special Objective in M1 Iron Dragon
W. Jacobs
complete Special Objective in M2 Eager Smoke
N. Tunney
complete Special Objective in M3 Stone Bell
J. Stone
complete Special Objective in M4 Black Needle
B. Gordon
complete Special Objective in M5 Gold Mountain
H. Ramirez
complete Special Objective in M6 Witch Fire
K. Henkel
complete Special Objective in M7 Paper Angel under
G. Osadze
complete Special Objective in M8 Zebra Straw
L. Cohen
complete Special Objective in M9 Blue Storm
A. Galinsky
complete Special Objective in M10 Fever Claw
S. Grey
complete Special Objective in M11 Dream Knife
D. Munz
complete Special Objective in M12 Ivory Horn
S. Ibrahim
Unlockable Maps
Complete the Campign once on Recruit.
Map MP07 Stronghold
Complete the Campign once on Veteran.
Map MP08 Creekbed
Complete the Campign once on Elite.
Map MP09 Wilderness
Unlockable Weapons
Complete Special Objective in M7 River, in Veteran during Mission Mode.
PKM for Guram Osadze
Complete Special Objective in M11 POW Camp in Elite during Mission Mode.
M60 for D. Munz
Complete Special Objective in M1 Caves in Veteran during Mission Mode.
7.62 Carbine for W. Jacobs
Complete Special Objective in M4 Village in Elite during Mission Mode.
AN-94 for Buzz Gordon
Complete Special Objective in M2 Farm in recruit during Mission Mode.
Bizon 9mm for Nigel Tunney
Complete Special Objective in M6 Castle in Elite during Mission Mode.
A-91 for Klaus Henkel
Complete Special Objective in M9 Swamp in Veteran during Mission Mode.
7.62 Sniper for A. Galinsky
Complete Special Objective in M12 Docks in Veteran during Mission Mode.
M98 for Scott Ibrahim
Complete Special Objective in M3 RR Bridge in Elite during a Quick Mission in Mission Mode.
Silenced Sniper for Jack Stone
Complete Special Objective in M10 Vilnius in Veteran during Mission Mode.
5.56 Carbine for Susan Grey
Complete Special Objective in M8 Battlefield in a Quick Mission in Mission Mode
7.62 AR for Lindy Cohen
Complete Special Objective in M5 Embassy in Recruit.
AK-74 for Henry Ramirez
Unlockables
Get wounded during a mission
Purple Heart
Get 15 kills
Bronze Star
Get 20 kills
Silver Star
Get 25 kills
Distinguished Service Cross
Get 30 kills
Congressional Medal Of Honor
Complete M15 Red Square in Recon on Elite using only a sniper with the M24 and frags kit
Paper Mode
Complete M06 Castle in Firefight on Elite, using only a sniper
Cat and Mouse Game
Complete M05 Embassy in Firefight on Elite, using only a sniper
Siege Game Type
Complete M13 Airbase in Firefight on Elite with a full team, and not losing a soldier
Helium Mode
Complete M15 Red Square in Firefight on Elite, using only a sniper
Domination Game Type