David Van Horn

This is a simple implementation of Tetris, developed using the design
recipe of HtDP.  It uses Scheme Unit for test cases.

To play the game, require the library and invoke the _play_ procedure
with no arguments.

  (require (planet "" ("dvanhorn" "tetris.plt" 1 0)))

Keyboard actions:

   A - clockwise rotation
   S - counterclockwise rotation
   Left - move left
   Right - move right
   Down - jump down

The game is currently written to include a "ghost peice" that shows
where the current tetra would land.