The music on this album is quite different from Tangerine Dream’s first album Electronic Meditation, partly because of a heavier reliance on keyboards and electronic technology, although they still mostly remain in the background: the dominant instruments on the album are organ and flute. The other difference is that this album focuses on dark, spacey soundscapes as opposed to jam sessions. The shift in instrumentation resulted in an atmosphere dubbed by Edgar Froese himself as "kosmische musik".Julian Cope's Head Heritage wrote that the album "used the space rock template from[Pink Floyd's] [A] Saucerful of Secrets (and removed the rock)".
A nowadays extremely rare single "Ultima Thule" was released in the same year. Side 1 employs the same guitar riff as "Fly ...", but the single was at the time otherwise an unconnected release. Re-releases of Alpha Centauri in the 2000s have however included either or both parts of Ultima Thule as bonus tracks.