Gran Turismo Sport's PlayStation VR mode "has only been in earnest development for 'four months'", according to a new report by Ars Technica.

The site claims to have been given the time frame by Sony representatives at last weekend's PlayStation Experience. And it "certainly feels that way," the report says, "thanks to an unfortunate mix of paltry graphical quality and uneven frame rates".

Gran Turismo Sport had originally been expected to be playable entirely in PlayStation VR, after director Kazunori Yamauchi revealed that he was planning to "allow all aspects of [the game] to be experienced in VR".