Here is the full list of all 14 Outback Survival achievements.
Survived a whole day without dying
Give a snake a cuddle
Survived 10 days without dying
Survived 20 days without dying
Go 12 rounds with a Kangaroo and win
Kill 30 undead with a cheval de frise
Kill 50 undead with a cheval de frise
Kill 100 undead with a cheval de frise
Build your first non-player item
Build 50 non-player items
Build 100 non-player items
Kill 30 undead
Kill 100 undead
Kill 500 undead