Cocker’s choice of “The Letter” seems dubious as well. This number was done to perfection the first time out by the Box Tops. Cocker’s version has its moments (as when he sings with very restrained accompaniment, merely drums, piano, and a very subtle horn sound), but it sinks under its own weight when all the horns and cymbals and girls and boys clamber in to enlarge the music. “Space Captain” predictably is one of the currently fashionable optimism anthems—it sounds as if it was more fun to record than it is to listen to it. It seems a tragic waste of talent and spirit for Cocker and his friends to spend their time assuring the world and the rest of us that all’s well, when a glance outside any window will tell you it’s not. Musically, “Space Captain” is a stunning bore. There’s no tension here. Cocker’s new music, as represented on this single, is flaccid.
Rolling Stone, May 14, 1970