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