The Medium

The Medium contains at least 79 collectibles required for achievements sorted into various types. The important ones include:
- 32 Echoes (Some echoes are also Henry's Echoes)
- 10 Memory Shards
- 11 Postcards
- 19 Troubled Man's Notes (Thomas' Notes)
- 7 Mentor's Diaries (Richard's)

An important note is that The Medium does not have chapter select, or achievement tracking, and all collectibles must be collected in the same playthrough for the achievement to unlock. However, some collectibles can be tracked through an in-game menu.

You can also find collectibles such as photos, eerie drawings, and "other", but these are not required for the achievement. You can see all the collectibles in this video below:
Famished Feline Achievement - 0:27
Photo 1: Jack - 0:54
Postcard: Niwa Says Hello - 1:12
Eerie Drawing: Someone New - 1:33
Echo 1 - 2:00
Postcard: Honest Work - 2:38
Echo 2 - 3:12
Postcard: Promotion - 3:35
Echo 3 - 3:59
Memory Shard 1 - 4:40
Echo 4 - 5:30
Mentor’s Diary: An Apology - 5:30
Memory Shard 2 - 6:12
Echo 5 - 6:43
Eerie Drawing: Lonely - 7:03
Troubled Man’s Notes: A Peaceful Place - 7:30
Eerie Drawing: Old Man - 7:30
Troubled Man’s Note: To-Do List - 8:05
Troubled Man’s Note: Getting Stronger - 8:35
Photo 2: From Hiding - 8:35
Troubled Man’s Note: Fever Dreams - 9:02
Echo 6 - 9:24
Echo 7 - 9:53
Echo 8 - 10:13
Postcard: Someday - 10:36
Troubled Man’s Note: Good Old Frank - 10:51
Echo 9 - 11:11
Echo 10 - 11:39
Echo 11 - 12:02
Echo 12 - 12:32
Other: Torn Illustration - 13:11
Echo 13 - 14:11
Eerie Drawing: Bad Nursie - 14:41
Eerie Drawing: Dark - 14:59 (Split Path: Male Soul)
Echo 14 - 15:23 (Split Path: Male Soul)
Echo 15 - 15:49 (Split Path: Male Soul)
Postcard: A Scenic View - 16:25 (Split Path: Female Soul)
Echo 16 - 17:15 (Split Path: Female Soul)
Echo 17, 18, 19, 20 - 17:45 (Split Path: Female Soul)
Other: A Quiet Girl - 18:40
Echo 21 - 18:40
Other: Empty Eyes - 18:40
Troubled Man’s Note: Dust and Death - 19:33
Echo 22 - 20:39
Mentor’s Diary: Throwing Away Greatness - 20:39
Mentor’s Diary: A Very Special Boy - 21:07
Memory Shard 3 - 21:23
Mentor’s Diary: A Well of Inspiration - 21:54
Mentor’s Diary: A Method to Madness - 22:09
Memory Shard 4- 22:28
Echo 23 - 23:07
Memory Shard 5 - 23:07
Mentor’s Diary: Growing Apart - 23:07
Mentor’s Diary: A New Hope - 24:18
Memory Shard 6 - 24:46
Memory Shard 7 - 25:09
Memory Shard 8 - 25:31
Postcard: Won’t Stop - 25:59
Echo 24 - 25:59
Postcard: Poor Thing - 26:39
Postcard: Harder and Harder - 26:57
Postcard: Whispers in the Dark - 27:24
Postcard: A New Companion - 27:46
Photo 3: Staff Photo - 28:02
Postcard: Regrets - 28:02
Echo 25 - 28:32
Echo 26 - 28:32
Echo 27 - 29:10
Troubled Man’s Note: Hell’s Angel - 29:10
Echo 28 - 29:45
Echo 29 - 30:09
Troubled Man’s Note: Something Broken - 30:09
Memory Shard 9 - 30:35
Memory Shard 10 - 30:58
Troubled Man’s Note: Demons - 31:28
Troubled Man’s Note: The Missing Piece - 31:50
Troubled Man’s Note: Found A Way - 32:27
Echo 30 - 32:39
Echo 31 - 32:39
Echo 32 - 32:39
Troubled Man’s Note: A Different Kind of Sickness - 33:37
Troubled Man’s Note: Separation - 33:48
Troubled Man’s Note: A Relic of the Past - 34:08
Troubled Man’s Note: A Thin Line - 34:29
Troubled Man’s Note: Just Me and Her - 34:52
Troubled Man’s Note: Keeping Distance - 34:52
Troubled Man’s Note: Business Card - 34:52
Troubled Man’s Note: Alone - 34:52