Brothers a Tale of Two Sons

After you get past the wolves at the start of Chapter 3, as soon as you drop the fire torch there is a statue off to your right, stand at the bottom of the statue and press and HOLD the RT button until you see a shooting star (I used the little brother so I used RT but I think you can use either brother, use LT if using older brother), after a few seconds holding button the achievement should pop.

This guide will walk you through all of the achievements in just 2 hours, timestamps are below the video


ACHIEVEMENTS LIST TIMESTAMPS
0:00 – Intro and Prologue
3:27 – Take a Break Achievement
10:37 – Chapter 1
10:57 – Wishing Well Achievement
14:39 – Love Birds Achievement (Part 1/2)
15:00 – Bunny Buddies & Black Sheep Achievements
24:14 – Chapter 2
42:45 – Chapter 3
44:06 – Falling Star Achievement
51:55 – Chapter 4
52:15 – A Sad Tune Achievement
58:00 – Windpipe Achievement
59:50 – Love Birds Achievement (Part 2/2)
1:14:03 – Chapter 5
1:18:00 – Call of the Giants Achievement
1:23:34 – Chapter 6
1:24:06 – Behind the Curtain Achievement
1:28:10 – Turtle Soup Achievement
1:30:45 – Whale Song Achievement
1:38:04 – Chapter 7
1:54:26 – Epilogue