Discover the secret of Valhalla

Send 15 zombies to their doom in the bottomless pits.

Get five headshots with the Crossbow in quick succession.

Maim 10 zombies with gardening equipment in the Cul-De-Sac's tall grass.

Protect the survivors

Complete your first mission

Unlock access to the Constructor Hero

Unlock and Slot your first Mission Defender

Complete "Rescue the Survivors"

Complete "Retrieve the Data"

Complete "Before and After Science"

Successfully complete expert mode.