Using Buster Keaton in the twilight of his career was an interesting choice. He may have been the most talented comedian of the silent age. This gives him a chance to display those talents in a little time travel story. He get hooked up with a guy living in modern times, and it becomes obvious that we are best left in our own times Keaton is able to do his sight gags very well. I've heard his voice before. I believe he did some of those Beach Party films, playing some vacuous characters just to earn a few bucks. Serling seemed to have respect for him and portrayed him that way. It's not a bad story. It shows how one reacts when we wish for something we don't have and get that wish.