Sustain a 6x multiplier for 60 seconds.
Complete a full issue without taking any damage.
Complete 5 Story issues in Co-op mode.
Complete any Story issue in Co-op mode.
Use Lori's Assassinate skill to KO 50 enemies while invisible.
Upgrade a skill for either Rick or Lori.
KO 100 enemies by throwing them against the panel edges
Defeat the final boss in any mode (Story or Co-op)
As Rick, KO 50 enemies with thrown objects.
Earn 75K points in Survival mode.
Unlock Rick's entire skill tree.
Unlock Lori's entire skill tree.
