Fantastic Contraption is one of the launch games for the HTC Vive (reviewed here) but it’s no longer included in the free game bundle. Fortunately, the price has dropped from $40 to $30.
There’s also a new level editor that will be added to the game. Here’s a preview:
Fantastic Contraption will also be available for the Oculus Rift in late 2016 (presumably after Oculus Touch becomes available).