This play is one of Shakespeare's richest in characters, themes and set-piece scenes. Falstaff needs no introduction: the fat man who fears shame and yet represents humanity, irresponsibility and the common-sense approach to the concept of honour (that it does not help you when you are dead!) Hal, his companion in the ale house, knows he must give up Falstaff's company when he is King and he prefaces this renunciation (which occurs in Part II) at the end of the marvellously comic scene of role-playing in the inn. "Banish plump Jack, and banish all the world," says Falstaff, playing Hal who answers, "I do, I will" speaking as the King. No-one knows of Hal's soliloquy in which he reveals to the theatre audience that he will reform when crowned, and his father is justifiably alarmed at his behaviour when he needs him to help put down the rebellion. Hotspur, one of the rebels, shows another version of irresponsibility: inability to keep his temper and an impulsive nature where his honour is concerned, to say nothing of incompetence: "I have forgot the map!" Shakespeare alters his actual age to make him a contrast to Hal and his death on the battle field is moving as the young man seems to stammer his last words. Another set piece is the robbery (not serious as they give the money back) where Falstaff hilariously exaggerates the number of his opponents but there is an underlying serious political side to the drama: war is harsh and a king must make cruel decisions particularly when his throne is insecure. Falstaff does die of a broken heart at the start of Henry V as a result of his treatment by Hal.
(I am less of a fan of the Arden editions than some reviewers as I find that the footnotes intrude on the text too much)