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