Here is the full list of all 26 STEINS;GATE ELITE achievements.
Played through everything in STEINS;GATE ELITE
Completed all endings.
Reached Steins Gate.
Saw all TIPS.
Chapter 10 Clear
Asked by Kurisu to buy cup noodles twice in a row.
Reached Kurisu's ending.
Offered tea by Faris.
Made friends with Kurisu via email.
Received an unusual proposition from Suzuha.
Learned about Luka's relationship to his sister.
Reached Mayuri's ending.
Chapter 9 Clear
Chapter 8 Clear
Reached Luka's ending.
Chapter 7 Clear
Reached Faris's ending.
Chapter 6 Clear
Reached Suzuha's ending.
Chapter 5 Clear
Learned why Mayuri started making costumes.
Chapter 4 Clear
Chapter 3 Clear
Chapter 2 Clear
Chapter 1 Clear
Prologue Clear