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