You need to charge through 20 enemies - Army of TWO: The 40th Day
You need to shoot 2 enemies in the head with a single bullet - Army of TWO: The 40th Day
Unlock every member of Team SSX through World Tour (or purchase in Explore or Global Events) - SSX
431/3,549310/1,25022/58
86/1,63570/1,0005/38
106/2,60150/4004/30