I seriously love the amount of detail and thought Bong Joon-Ho put into this movie. For example during the scene where the victim looks back after hearing the serial killer's whistling, you can see in the background the serial killer's head peaking out of the tall grass out of focus as the victim points her flashlight to the opposite direction. Like holy shit I got goosebumps spotting that head pop out of nowhere then disappear like it never happened.