Here is the full list of all 34 CHAOS;CHILD achievements.
Mastered Chaos;Child
Saw All Event CG
Listened to All Sound
Reached the Silent Sky End
Saw All TIPS
Reached the Real Sky End
Discovered the True Route
Saw All Negative Delusions
Tried All Delusion Triggers
Saw All Positive Delusions
Discovered Nono Kurusu’s Chapter
Made No Mistakes When Putting Up The Data
Reached the Deep Sky End
Discovered Hana Kazuki’s Chapter
Reached the Dream Sky End
Discovered Uki Yamazoe’s Chapter
Reached the Bad End
Reached the Dark Sky End
Discovered Hinae Arimura’s Chapter
Got It Wrong On a Mapping Trigger 20 Times
Reached the Over Sky End
Started Chapter 11
Started Chapter 10
Started Chapter 9
Started Chapter 8
An Amazing Wind Blew
Started Chapter 7
Started Chapter 6
Started Chapter 5
Started Chapter 4
Started Chapter 3
Started Chapter 2
Didn’t Get Scared, and Tried a Delusion Trigger
Started Chapter 1