Here is the full list of all 29 Hotline Miami 2: Wrong Number achievements. It takes around 40-50 hours to unlock all of the achievements on Windows.
Perform a 20x combo
Clear all of the Writer's levels without killing
Clear a level with each snake mask
Finish SUBWAY without the Gang Leader seeing you
Clear a level with each of the Son's techniques
Use every weapon in the game at least once
Finish the game on hard mode
Destroy 100 electronic devices
Clear a level with each Fan
Shoot two enemies during a chainsaw finish
Unlock THE ABYSS
Clear the 1st floor of NO MERCY with the silencer
They won't reach the Nuclear Throne
Meet up with the Biker
Finish the game
Unlock all of the Son's techniques
Perform a 15x combo
Unlock all weapons for the Soldier
Unlock all snake masks
Die 1000 times
Perform a 10x combo
Unlock all the Fans
Finish HOMICIDE without using guns
Perform a 5x combo
Do as the Director says!
Unlock all achievements
Get A+ on all levels on normal
Get the big picture
Kill 50,000 enemies