Arrow Keys	Move left, right and down
Spacebar	To pause the game
'A' Key	To rotate your shape
Start	Click Start to play!

It's tetris, if you haven't played before you can read the basic rules here.
Get the highest score you can before the board fills up!
You get bonus points for the more lines you clear at once:

1 row	0 bonus points
2 rows	100 bonus points
3 rows	400 bonus points
tetris*	1200 bonus points
back-to-back tetris	5000 bonus points

^{*a tetris is when you clear 4 rows at once}