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