Hexy
In January 2017, I sat down to learn about the Unity game engine and also how to make an Android Gear VR game with it.
An excavator simulator would be a perfect VR experience. After about a month or so, I now have a working knowledge of Unity and the Oculus VR SDK and a little working demo.
You are inside of an excavator and use a wireless gamepad for controlling the treads and the arm. Being inside of a cab helps with potential motion sickness. My next goal is adding deformable terrain, but that is a big task.
Hexy is open source!