Here is the full list of all 20 Immersive Poetry achievements.
Collect 5 Groups of Mushrooms
Collect all Poem Parchments
Investigate the Blue Object
Enter the Gate with no Gate
Enter the Correct Code
Find the Music Box
Find your Wife's Glasses
See the Submarine
Complete the Sixth Level
Leave your Journal Behind
Collect 5 Poem Parchments
Complete the Fifth Level
Complete the Fourth Level
Complete the Third Level
Collect 3 Poem Parchments
Reset your Progress
Complete the Second Level
Take a Photo with the In-Game Photo Mode
Complete the First level