Here is the full list of all 27 How To Survive: Third Person Standalone achievements.
Enter Santa Barbara Island
Perform 100 instant kills.
Enter La Sonada Island
Kill 5 zombies in less than 5 seconds.
Enter La Vendida Island
Unlock your first skill
Achieve your first instant kill on a zombie.
Find the 20 special plants of the Herbarium.
Complete the story mode in "Normal" difficulty.
Complete a challenge with a "S" ranking.
Complete the 12 secondary quests of Kovac's monkeys.
Reach "Survival hobbyist" ranking tag (Challenge mode)
Complete the story mode in "Iron man" difficulty.
Complete a challenge in "Normal" difficulty without using medicinal plants nor medikits.
Complete a challenge in "Iron man" difficulty without using medicinal plants nor medikits.
Complete a challenge in "Normal" difficulty without losing health.
Complete a challenge in "Iron man" difficulty without losing health.
Kill 10 zombies in less than 5 seconds.
Kill 20 zombies in less than 5 seconds.
Kill 1000 zombies
Kill 2000 zombies
Get zombies deer to kill 20 Zombies.
Perform 5 instant kills in less than 15 seconds.
Kill 5 monsters in a row with a bullet or an arrow.
Complete the mode "One Shot Escape" in "Easy" difficulty.
Complete the mode "One Shot Escape" in "Normal" difficulty.
Complete the mode "One Shot Escape" in "Iron Man" difficulty.