Here is the full list of all 46 Silence achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Discover every possible Spot form
Fall in all balance checks or fall in the same check 3 times
Sneeze over the candle
You finished chapter two
Completed the prayer mill story with the life wheel
Let Renie and Noah both pop the bubble
Look into the abyss
Burn the swamp
Taste the everything in the swamp
Lick the mushrooms until you pass out
You finished chapter one
Drop the Noiseball
Prime the bomb
Pull the world worm's tooth
Finish the game without dying
Let Sadwick die every time it's possible
You finished chapter three
Go through the mirror
Stay in Silence
Finish the game without using the snoopkey
Finish the game without skipping a text
Let spot fly
Spot licked everything
Find all bugs
Find all possible Spot interactions
Don't prime the bomb
Trigger the same game over sequence twice in a row
Let the mushroom fart ten times
Shoot the gate
Send Spot to Kyra
Fix the bomb without letting go
Use the magic boxes to change into all available Spot forms
Let the fish get the berries 3 times
Hit Kyra
Kick everything possible
Play with the shadows
Balance without falling down
Listen to Kyra
Spot plunges everywhere
Dive through the clouds
Get to the gate in 8 steps
Place candles everywhere possible
Grab 10 gold from the well
Completed the prayer mill story with the death wheel
Completed the prayer mill story with the dream wheel
Skip every puzzle