time codes:
0:00 - foreword
1:50 - first level
3:15 - photography mom, dad, me, achievement "Mom, Dad, and Me"
5:15 - first floor
7:05 - second floor
7:47 - third floor
7:59 - photo on the third floor
8:52 - fourth floor
9:30 - fifth floor
10:10 - sixth floor
11:30 - seventh floor
11:45 - photo on the seventh floor
12:08 - pen on the seventh floor and achievement key, achievement "The Key"
12:40 - eighth floor
15:00 - ninth floor
15:17 - photograph on the ninth floor
15:52 - tenth floor
17:02 - eleventh floor
18:05 - twelfth floor
18:43 - yellow feather on the twelfth floor
18:55 - photograph on the twelfth floor
19:20 - thirteenth floor
20:42 - fourteenth floor
21:49 - fifteenth floor
11:35 - venus flytrap
24:05 - sixteenth floor and photography
25:20 - seventeenth floor
25:55 - two photos on the seventeenth floor
26:45 - crystal ball on the seventeenth floor
28:35 - santa calus on the seventeenth floor, achievement "Jolly Old St. Nicholas"
29:20 - eighteenth floor
29:42 - blue toy bird on the eighteenth floor
30:22 - the toy bird itself
31:00 - nineteenth floor
32:05 - twentieth floor
33:49 - book for achievement, diary on the twentieth floor
34:22 - cloud machine
36:00 - Mr. Keith
38:20 - Mini robot
40:00 - solving the puzzle to enter the secret office
41:10 - office entrance and photography
41:46 - by a secret path, achievement "Through the Hidden Path"
41:50 - office
44:55 - a lot of photos in the office in a row
47:40 - floor 3/4
48:45 - grandfather's room
48:45 - a lot of pictures in grandfather's room
49:25 - small triangle, achievement "The Little Triangle"
49:37 - more photos
50:17 - the best show on earth, achievement "The Greatest Show on Earth" and more photos
51:50 - golden key
52:25 - brush for grandfather
52:37 - paints for grandfather
54:00 - palette for grandfather
55:35 - photography and getting the achievement "The Photographs"
56:09 - the bottom of the rocket
57:37 - middle part of the rocket
58:02 - photos in a rocket
59:50 - top of the rocket
1:03:25 - achievement "The Most Beautiful Tragedy"
1:03:50 - achievement "Friends"
1:04:55 - the world above the clouds, achievement "A World Above the Clouds", observation tower
1:05:10 - achievement "Old Man's Suitcase", achievement "The Old Man's Suitcase" and photos in a suitcase, achievement "Two photos", achievement "Two photos?"
1:07:10 - more photo
1:09:45 - Achievement "Lift Off!" Before you fly, go to the old man at the telescope, he will give another photo and the achievement "Final Goodbye".

time codes:
0:00 - introduction
0:20 - last goodbye, achievement "Final Goodbye"
0:52 - found, achievement "You Found Me!"
1:30 - about CottonGame, achievement "About CottonGame"
2:05 - waiting, achievement "Waiting"

gratitude to MOGUANYI for achievements You Found Me! and About CottonGame