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