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