To be perfectly blunt right from the get-go, Kid with the Golden Arm is not one of the best Shaw Brothers movies, but neither is it anywhere close to one of the worst. I feel like it's somewhat middle of the road, but as it turns out, middle of the road for the greatest martial arts movie production company in history is still very good overall, when all's said and done. There are problems, and there are nitpicks, but I feel like for this specific movie, it's so direct and unapologetic about delivering almost nothing but action that most flaws are quite easy to forgive.
This is usually the part in a review where I'd try to summarize the plot, but it's too hard to do for Kid with the Golden Arm. There is a bunch of gold being transported, and slightly too many characters are all wanting to obtain it. Some want it for selfish reasons, and some characters seem more altruistic (even if it's not always clear who's who - there are so many characters here, and they're really only distinguishable by their fighting styles, which you do get used to as the movie goes on).
People in this film all vaguely want the same goal, and the movie is 86 minutes of them competing for it. It feels like a 120-minute-long movie edited down so that most dialogue scenes that don't involve people expressing a desire to fight were cut out, leaving the movie clocking in at under 90 minutes. There's one stretch shortly after the halfway point where it feels like about 15 to 20 minutes pass without any action, and that's the closest things come to feeling boring (honestly, just take the opportunity to have a toilet break here without pausing, or top up your beverage of choice if you like to indulge in a drink or two when watching martial arts movies).
As for the action, I don't think it's top quality by Shaw Brothers standards, but it's fun. I liked certain characters having certain physical quirks/fighting styles, and there were a few wild moments that surprised me and made me laugh. It's a good time if you're a fan of classic martial arts movies, but it's certainly not representative of 1970s Hong Kong martial arts cinema at its very best.