Here is the full list of all 35 Planet of the Apes: Last Frontier achievements.
Best of all outcomes
Jess and Bryn sitting in a tree
Jess puts the big man in charge
An explosive ending
Mark demonstrates his feelings for Jess
A debt repaid
Bryn is a family man
Bryn opens the way to peace
Complete Chapter 4
Thaw relationship with Mark
Bryn makes an important choice
Bryn demonstrates brotherly love
Complete Chapter 3
Jess does what's necessary
Set an ape on fire
Bryn shows wisdom
Complete Chapter 2
Bryn covers up a mistake
Complete Chapter 1
Complete Prologue
Where have all the good guys gone?
Jess betrays confidences
Jess puts her life on the line
Apes together strong!
Damn dirty apes
Bryn is his father's son
Juno's downfall
Bryn shows his true colours
Bryn prefers deeds to words
Jess looks a gift horse in the mouth
Maria accepts her fate
Jess does the right thing
A chilling ending
Bryn shows no mercy
A rather pointed decision