Use the secondary fire of each weapon in the Single Player Campaign

Kill 100 Chimera with headshots in the Single Player Campaign

Kill 50 Chimera with Riley's axe in the Single Player Campaign

Successfully complete level 3

Kill 250 Chimera in the Single Player Campaign

Kill the Abomination

Successfully complete level 1

Upgrade a weapon in the Single Player Campaign

Combined two materials to make an item.

Complete File R-07: Assassination Attempt.

Complete File R-05: Escape From Denver.

Successfully complete 30 Ninja Kills during story mode.