The area where all the cubes are has a trigger collider on it
Should be a cube with 0.3 units on each side, encompassing the entire cube stack
When controller & trigger area collide, create a Unity Explosion
Use this on all cubes in scene: Rigidbody.AddExplosionForce, play w/ params to get something that feels right, but ballpark order of magnitude of effect should feel like a dangerous firecracker
Run a loop to wait for the condition of the VR controller collider NOT being inside the cube stack trigger collider. Once that's the case Destroy() all 6x6x6 cubes, and instantiate a new cubestack set to replace the original.
Make a prefab
Make a floor
Instantiate them so that they're stacked 6x6x6
(i = 0, i<6, i++)
User can smash cubes