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