As mentioned, movies have motion blur and very evenly delivered frames, but from my experience, one of the biggest differences not mentioned is the interaction between the game and what you see. When you watch a video, it does not matter how long it takes to deliver a frame, other than the end result, but when you game, that adds to latency and makes a game feel very sluggish. This is less noticeable with consoles, as controllers do not have the same connected feel that mice have. With a mouse, that low frame rate results in more latency and makes a game feel sluggish. For those with simulator sickness, as I have, it can even make you feel very nauseated, yet watching a movie at 25-30 FPS does not bother me one bit.