quadra

Live: http://www.ghosthack.com/quadra/quadra.html

• Use keyboard arrows to move the figures;
• 'space' or 'up' to rotate;
• pause the game using 'p';
• restart with 'r';
• and instantly drop with 'q'.

Source at gh-pages branch: https://github.com/ghosthack/quadra/tree/gh-pages