Diamond thin films have been grown using a cyclic growth-etch oxy-acetylene flame process on Si, W and Mo substrates. This process resulted into the growth of cubic diamond, 8H and 15R polytypes of diamond. The results suggest that cubic diamond grows with the formation of intermediate low-symmetry polytypes, Glancing angle X-ray diffraction (XRD) and micro Raman spectroscopy techniques have been used to characterize these films. The relative growth of various polytypes have been found to be a strong function of acetylene to oxygen flow ratio, speed of rotation and the substrate materials.