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