Stanley Donen’s Charade (‘63) is lightly charming but often silly and cloying and full of inelegant distractions. It’s engaging but not top-tier. I’ve seen it exactly once, and I felt vaguely bored throughout..
Charade was made only four years after North by Northwest, and yet Cary Grant appears to be late 50ish at best, or at least ten years older than Roger Thornhill appeared to be in Hitchcock’s film (i.e., 47 or 48).
Too old, in short, to play Audrey Hepburn’s would-be boyfriend, although Grant would have been perfect, Hepburn-wise, if he’d played Humphrey Bogart’s role in 1954’s Sabrina. Billy Wilder offered him this, but Grant declined — mistake.