It's A Trap! - In Shi No Numa, kill at least one zombie with three different traps in a single round.
The Eagle has Landers - In Ascension, escape on all three lunar landers.
Chimp on the Barbie - In Ascension, kill a space monkey with a fire trap.
Time Travel will Tell - In Shangri-La, acquire the Focusing Stone.
Small Consolation - In Shangri-La, use the 31-79 JGb215 on each type of zombie.
Cryogenic Slumber Party - In Moon, complete Richtofen's Grand Scheme.
Ground Control - In Moon, prevent each excavator from breaching the base in one game.
Little Lost Girl - In Origins, release Samantha.
Overachiever - In Origins, complete all 4 challenges in one game.
I said we're CLOSED! - In Nacht Der Untoten, do not let any zombie enter the building during the first round.
Acted Alone - In Verruckt, headshot 20 zombies in the courtyard from the second floor of the Asylum
I've seen some things... - In Kino Der Toten, visit every location the teleporter can take you to.