Less Than Zero is a bad film. Not much like the book, and just really badly made in places. There is a party scene where everyone is talking loudly, but there is no music. They go to the bathroom and you can hear a muffled Public Enemy blasting through from the party. They go back in to the party and speak loudly over nothing.
The Box has an interesting idea to start with and seems to be going somewhere. Would you press a button in the box for $1,000,000 but a stranger dies? Then is goes bat shit crazy - It involves NASA, the NSA, floating cubes of water, a wedding, kidnap, aliens, Sophie's choice, possible extermination of the human race. And finishes like this -
Steward offers Arthur and Norma a final choice: Walter is now deaf and blind. Either they live on with a disabled son, or Arthur can shoot Norma through the heart, at which point Walter's sight and hearing will be restored. Norma begs Arthur to shoot her. Elsewhere, a woman pushes the button on her box and Arthur shoots Norma, killing her. As Arthur is taken away by police, Steward leaves the other couple's house with the box. Walter is shown through an upstairs window in the home with his grandfather. The final scene shows Steward standing in the snow by his car, parked in a street, with the box.