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 Mum.
Accidentally come clean about cheating.
Accuse Nan.
Find the killer.
Accuse Lottie.
Praise mum too much.
Accuse Aunty June.
Accuse Bradley.
Accuse Toby.
Don't be persuaded by Toby to submit the wrong answer.
Answer that Lottie's biggest fear is baldness when playing with Nan.
Mum fools Toby into showing empathy.
Saved Uncle Marcus.
Don't be persuaded by June to submit the wrong answer.
Start the quiz.
Uncle Marcus reveals he has been poisoned.