Here is the full list of all 28 STEINS;GATE 0 achievements. It takes around 35-40 hours to unlock all of the achievements on Windows.
100% Completed Steins;Gate 0.
Saw all TIPS.
Saw all CG.
Cleared "Milky-way Crossing".
Cleared "Promised Rinascimento".
Cleared "Recursive Mother Goose".
Read and ignored a message.
Cleared "Antinomic Dual".
Cleared "Twin Automata".
Saw 75% of CG.
Cleared "The Orbital Eclipse".
Cleared "A Stray Sheep".
Cleared "Closed Epigraph".
Cleared "X-Day Protocol".
Cleared "Pandora's Box".
Cleared "Presage or Recognize".
Cleared "Vega and Altair".
Cleared "Gehenna's Stigma".
Opened Clear List.
Opened CG Library.
Opened Sound Library.
Opened Movie Library.
Opened TIPS List.
Saw 25% of CG.
Saw 50% of CG.
Answered a message from someone.
Cleared "Missing Link".
Began Steins;Gate 0.