Says the instruction booklet:

What is Tetris?

TETRIS is a new type of puzzle game from the Soviet Union. It's really simple to play. Seven different shaped blocks fall down the game field one after the other. The object of the game is to keep the blocks from piling up to the top of the game field. To do this, you can move the blocks to the left and right, and rotate them as they fall. If you can completely fill in one horizontal line, that line disappears and you get points. If the blocks pile up to the top of the game field, that's the end of the game. TETRIS is simple, easy-to-understand and difficult to drag yourself away from!

Now consider how many more rebellious youngsters of the post-Reagan era those folks at Nintendo could've attracted with this objective:

You are Mother Russia! You want to destroy those pesky capitalists with your armada of powerful rockets! To do so, you must disguise yourself as one of them-- as a creator of immense commercial buildings and skyscrapers, each of which are constructed out of seven primitive tetrads.... Watch those filthy Yankees and Western Europeans prosper in their domiciles and free markets! But then, when they least expect it, Ka-BLAM! Use a long tetrad (in the form of a missile, of course) to flatten their cities! The score will tally up how many gluttonous industrialists you have killed, or at least financially corrupted! Soon, the blasting of the Russian rockets will celebrate the final conversion of the world into one gigantic People's State! Ah ha ha haaaahhh!

Then again, maybe "get points or the game ends" is sufficient enough....