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