Watched this with my 3 year old for the first time today. It won't be the last.
He was a bit fidgety at the start when the droids were crossing the desert, and after Ben saved Luke from the Sand People. I distracted him while Luke sped home to see what became of his aunt and uncle. Apart from that scene, there was nothing that gave him any frights, but he was indignant when "Darth Vader shot R2D2, dad!!"
At the end, we both had triumphant fists in the air and ear-to-ear grins, cheering for Luke's bravery, Han's self sacrifice, Leia's awesomeness and R2's shiny paint job. I haven't enjoyed this masterpiece so much since the first time I saw it when I was 5. Just wonderful.
Archie wants to know "what happened to Luke's daddy, Daddy?". No one tell him. He's not ready for that yet. I can hardly wait. He wants to watch Star Wars again immediately. I can cope with that.