Here is the full list of all 17 Who Pressed Mute on Uncle Marcus? achievements. It takes around 3-4 hours to unlock all of the achievements on Windows.
Accuse every suspect.
Accuse Aunty June.
Accuse Toby.
Mum fools Toby into showing empathy.
Accuse Bradley.
Accuse Nan.
Find the killer.
Accuse Lottie.
Don't be persuaded by June to submit the wrong answer.
Accuse Mum.
Saved Uncle Marcus.
Answer that Lottie's biggest fear is baldness when playing with Nan.
Start the quiz.
Uncle Marcus reveals he has been poisoned.
Don't be persuaded by Toby to submit the wrong answer.
Accidentally come clean about cheating.
Praise mum too much.