Cubes, colored according to their location in a 4x4x4 grid with a light circling around the whole grid.

After you click on the window above, you can fly through the grid.
The location of the cursor on the window determines the direction you are facing.
To apply forward thrust, press the up-arrow.
To apply backward thrust, press the down-arrow.
To stop moving forward or backward, click the mouse.
To rotate a cube, click and drag on it (this will stop your motion too, but not your rotation).
The 'Level' button leaves you where you were, but orients you as you were at the start.
The 'Home' button does the same as 'Level' plus it puts you back where you started.