It's not about being punished for our sins as much as making us facing the consequences of our sinfulness by experiencing in ourselves the pain we caused in others.
But, a merciful God being in charge of the cinema, we are then shown another film -- of the kindness we bestowed and the good we did. I think this will be the more interesting and surprising film, since much of the good we do is far less known to us than the pain we caused. Examples: The smile we gave a drive-thru employee. The door we held open for an immigrant. The birthday greeting to a lonely person. The compliment to a co-worker. The time we felt stupid for having nothing to say to a grieving friend. The flower we placed on a gravestone.
At heart, most of us are good, though we don't give ourselves much credit. Wouldn't it be an interesting world if we obsessed as much about the good things we did as much as the dopey ones?