It is an WebVR game. You need a VR headset with controller to play it. Open the game with the Firefox browser or other WebVR enable Browser.
Or play the game in the Supermedium full VR browser.
All what you need to do, is to cross the street to the other side between the driving cars.
The HTC Vive is a virtual reality headset developed by HTC and Valve Corporation. The headset uses "room scale" tracking technology, allowing the user to move in 3D space and use motion-tracked handheld controllers to interact with the environment