Valve has technically made a new Portal game – but it’s solely a demo for developers using a new virtual reality controller.

‘Moondust’ is on Steam, though doesn’t appear in the main listings, instead being accessible only through a dedicated link. It’s arguable whether it’s actually a game, with perhaps a more accurate description being a ‘sandbox experience’.

The story as such involves building a space station and then testing technology on the moon. Activities including controlling a moon buggy, breaking tocks and throwing items about. It’s all part of the Portal universe, complete with the traditional dry humor.

The point is to show off the possibilities for the Knuckles EV2 controller. It’s a device you grip in your hand with the thumb operating face buttons, the forefinger controlling a trigger button, and the other three fingers using a “pinch grip” controller that’s designed to make the experience more immersive as you manipulate in-game objects.

Right now the controller – and thus the ability to play Moondust – is only available as part of a devkit.