Fun Fact #54 - Do you have a copy of Tetris for your NES? If so, you might want to dig it out and check which version you have stashed away. The Tengen copy (Tengen being Atari's publishing arm) is thought to be in limited quantity—with only around 100,000 copies still in existence. The Tengen version preceded Nintendo's own version of Tetris, but was pulled off the shelves.