Here is the full list of all 24 Volume achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Complete 25 core levels
Complete 50 core levels
Travel 1 mile
Travel 3 miles
Play for 20 minutes
Read 25% of text in the core levels
Read 50% of text in the core levels
Jump 25 walls in the core levels
Be seen by enemies 300 times in the core levels
Die once
Fire the bugle 50 times in core levels
Place 20 follies in core levels
Complete 75 core levels
Complete all core levels
Read 75% of text in the core levels
Read 100% of the text in the core levels
Hide in 50 lockers in the core levels
Stun enemies 100 times in the core levels
Die 200 times
Play a level with a customized character
Go invisible 30 times in core levels
Fire 40 figments in core levels
Wear a disguise 100 times in core levels
Use every gadget in the core levels