I adore this short. I watched it as a kid, and it's got even better, watching it as an adult.
It's got the lovable "everybody's" grandmother who can first read a scary story to the kids and then don the boxing gloves and duke it out. It's got a son-in-law of pure evil, who would not only steal money from Granny (twice), but also break her glasses on purpose, right before he sends her to the Poor Farm.
But best of all, it's got kids who act like true kids. They return Granny's unconditional love, and also defend her from the dark-suited wraith. The best part for me is when they bite the guy! Because when you're a little kid, you're virtually defenseless against a big adult. And you're always taught to never bite. But when it's all they can do, the kids do it, and it's satisfying because the guy deserves every bit of it.
Also satisfying are the other ways they get even with him. It may seem cruel to drag someone's butt over broken glass and rusty nails, but it's a riot when it happens to this guy. I don't think you could make this sort of thing today and have it be funny. The secret here is that it's so in-your-face that you can't help but laugh. We all think things were so quaint back then, but comedians were just as out there as they are today.
Anyway, I'm sure this film was satisfying to period audiences, with James Mason personifying the depression, and Margaret Mann as the "everyman" Granny who regular folks could identify with. She even says at one point "Burn those papers--let them go up in smoke just like all my dreams and hopes."
The character development is quick, the dramatic build-up pulls you right in (just as you can't believe how mean Mason is, he gets meaner), and then the kids save the day, along with a wonderful contribution from Pete the pup. I don't think I'll ever get tired of watching this short.