Hi Bhavesh,
Alternative to devlop mobile VR Games would be only UNITY (if world viz provides plugin ). You may pls refer and get some points by visiting the link and develop VR Game Natively using the Google SDK:
https://developers.google.com/vr/android/
Thanx & Regards:
Mr.Rajnish Vishwakarma
Software Developer at Xenium Digital Pvt ltd,Mumbai