Tetr-ish

A and D - Move tile left and right

S - Drop tile (cancel by pressing any other key)

J and L - Rotate tile

You score points for:

• Every row you fill and clear from the board. Bonus points for clearances in quick succession, inversely proportional to the time between them.
• Every tile that lands on the board.
• Every square a tile moves downwards whilst you are pressing S.