Here is the full list of all 9 Bloody Walls achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Finish the game
Сomplete the task - "Microchip"
Kills 100 enemies
Сomplete the task - "Transistor"
Сomplete the task - "Cookies"
Сomplete the task - "First aid kitt"
Kills 50 enemies
Kills 10 enemies
Сomplete the task - "Teddy bear"