(Re)Implementing Tetris
Try: http://tetris.muehe.org

Update There's a global high score. Enjoy beating it or - alternatively - hacking it :-)



CoffeeScript and HTML version, should fulfill the requirements to the best of my knowledge (and I have never really played Tetris). 

$ make stats
4095


Github https://github.com/henrik-muehe/tetris

Features


Exponential scoring
Next piece indicator
Fair randomness
Rotation, move and drop down
Game over indication
Highscore with server backend that should not be that easily fakeable.