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 Nan.
Find the killer.
Accuse Aunty June.
Accuse Toby.
Accuse Mum.
Praise mum too much.
Accuse Bradley.
Accuse Lottie.
Mum fools Toby into showing empathy.
Don't be persuaded by Toby to submit the wrong answer.
Don't be persuaded by June to submit the wrong answer.
Accidentally come clean about cheating.
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.