Mission Complete
Overthrow Putzki and liberate Albatropolis
Dirty Half-Dozen
Complete the Cooperative game mode
Hardboiled Seal
Kill 100 penguins or clones
Hardboiled Orca
Kill 300 penguins or clones
Disgruntled Worker
Find 3 Signs
Rebellious Laborer
Find 20 Signs
Revolutionary Fighter
Find all 45 Signs
Flight Instructor
Juggle an enemy for 10 seconds
Own Medicine
Kill a helicopter penguin with his own missile
Own Pharmacy
Kill 6 helicopter penguins with their own missiles
Hydrogen Run
Escape the large zeppelin with 40 seconds or more on the timer
Door Sentry
Kill 30 Penguins as they step out of a door
Brainbug Fever
Brainbug 30 enemies
High Treason
Brainbug the penguin above the star in Chapter 6 (Single Player)
Turncoat
Kill 20 enemies while brainbugging
Bird Brained
Brainbug at least one penguin from each of the 7 penguin ranks, including Putzki
Fear the Spur
Kill Brno with the knife
Two Birds One Stone
Kill 2 enemies with one grenade
Too Many Too Soon
Kill 3 enemies with one grenade
Bazookin'
Kill 6 enemies with the bazooka
Friendly Transit
Carry the other cooperative player for 500 meters in the same chapter without dying
For What Reason?
Launch the silo missile
Personal Space
Punch or kick 100 times
One Shot One Kill
Kill 10 enemies, each with one gunshot
Laser Assist
Kill an enemy by knocking him into a laser door
Excessive Stacking
Stack all 3 crates near the end of Chapter 11 (Single Player)
Hindenburger
Kill all penguins stationed on the zeppelin in Chapter 3 (Single Player)
Dirigibully
Kill all penguins stationed on the small zeppelin in Chapter 8 (Single Player)
Big Blimpin'
Kill all penguins stationed on the big zeppelin in Chapter 8 (Single Player)