ZIGGY'S WARRING PLANETS
=======================

Welcome to Ziggy's Warring Planets, the game of timing, gravity,
and good fun.  Earth and Mars have been taken over by mammoth,
powerful alien peoples who have turned our solar system into the
stage for their sport of interplanetary war.

Each planet has been eradicated of familiar life, and the only
features left are a massive land-to-space gun located on the
surface and, diametrically opposite, a rocket thrust station that
pushes the planet through space.  I shudder to think what they are
using as fuel for this station (gulp).


OBJECT OF THE GAME
==================

The object of the game is to shoot down your opponent's planet. 
Every successful hit scores one point for the shooter.  A point is
also scored if your opponent crashes into the sun.  If the two
planets collide with each other, each scores a point.

The force of gravity acts on all objects in the field of "play". 
Both planets are attracted to each other and to the sun. 
Additionally, the bombs fired are attracted by the gravity of the
sun and the targeted planet.  The higher the gravitational constant
(which is adjustable), the more likely a bomb is to make contact
with its target.


HOW TO PLAY
===========

Even these monstrous aliens have not managed to stop the worlds
from turning.  They can therefore shoot in a given direction or
push off in a given direction only once per "day".  It is
important, therefore, to plan your moves carefully.

In addition, they can only shoot a bomb once their latest bomb has
exploded.  This will happen if it hits the sun, its target, or
expires.  It is likewise important, therefore, to plan your shots
carefully.

Those, then, are the only two operations ... thrust and fire.  The
default key assignments for these operations are:

BLUE PLANET:            THRUST: q                       FIRE: e
RED PLANET:             THRUST: p                       FIRE: i


OPTIONS
=======

Each time the program is run, players are asked to customize the
game the way they like:

  Firstly, each player is asked to enter a name (up to 18  
  characters).

  They are then asked to decide whether or not the sun exists (use
  your imagination).  A game with no sun requires accurate shooting
  and quick reflexes, but will quickly lose its appeal to the    
  experienced player.

  The GRAVITY CONSTANT relating the acceleration of a body to the 
  mass and distance from the gravitational source is then required.
  A comfortable value is 100, but anything between 0 and 999 can 
  be selected.  High gravity constants should probably be reserved 
  for games with no sun.

  The next option sets the GAME SPEED.  The lower the number, the
  faster the game.  A speed of 7 is suggested, but the speed of the
  computer will determine the best value.  Experiment.

  The NUMBER OF HITS that will make up the game is then chosen. 
  Up to 9 hits can be selected.  Each time a planet explodes, the
  scoreboard is displayed and a hit is used up.  Note that if both
  planets explode, only one hit is used.

  Finally, the choice of TOROIDAL or BOXED space must be made.  In
  toroidal mode, planets reaching the top of the screen will    
  reappear on the bottom, and planets reaching the side will    
  reappear on the opposite side (imagine attaching the top and   
  bottom edges of the screen and the left and right edges ... you 
  get a donut or "toroid").  In boxed mode, the planets bounce off
  the edges of the screen.  Bombs disappear at the edges in either 
  mode.




CONCLUSION
==========

Enjoy the game.  If you like it, please e-mail me at:

		mfruman@physics.utoronto.ca

and tell me so.  Any suggestions are welcome.  Please save the
vicious criticisms for games that you pay for.

Mark Fruman
July 1997

(updated September, 1999)