For most of this movie I thought I'd wasted an hour and twenty minutes of my life. Mostly crummy performances, of course Jimmy Stewart as Rupert being one of the exceptions. Shooting the whole movie in "one shot" gimmick got old real quick. I didn't understand or care for the two murderers (Farley Granger and John Dall), and frankly they seemed like pests that you try to shoo away. They wanted to be understood but that's as far as they got.
Then once the movie was coming to a close, I realized because of the limitations there was no way this film was ever going to be that good. It should be treated more of an exercise of Hitchcock's rather than something that should rake in praise. We know that someone has to find out about the body at the end of the movie, and we know Rupert's going to be the one to do it. We know for storytelling that we need to trick the protagonists into thinking they've been successful, so everyone needs to leave the party at first. Then of course Rupert is going to call and come back and find out. It's all predictable, but under the circumstances that's the only way it could've gone down. Even during the beginning moments it seemed like Rupert already read the script. The whole thing just was not believable. The only part that I was on edge for was when Jimmy opens up the chest to put away the books before Brandon (Dall) stops him. Rupert blowing their cover by shooting bullets out the window was a great touch as well.
So to see this film as an experiment—for the sole purpose of taking bold risks—where the only one that gets anything out of the work is Hitchcock: who, falling on his face, can pick himself back up and learn from the mistakes. But it's from this movie where we can see precursors of Vertigo and Rear Window. The green light from the neon sign pouring in from the window, the idea of a neighborhood murder hidden using everyday tools—it's all there. In a youtube interview with Scorsese and Coppola they talk about how all their films were experiments, and all the masters certainly have that in common. Though I'd be hard pressed to find a time in the near future where I'd have a desire to see this movie again straight through.