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