Man it has been a long time since I played this game. Block Out by California Dreams is one of the original versions of 3D Tetris – and it is still quite an addictive game. Running in a combination of CGA and EGA graphics you are required to maneuver 3D blocks as the fall down into a pit – with the aim of making complete levels (so they will then disappear). I personally find Block Out to be both more challenging and more entertaining than standard Tetris:
And it runs perfectly under Virtual PC (on Vista no less).