This is a clone of Yars' Revenge, an odd game for Atari 2600 involving space
flies, swirls, and other assorted madness. For background on the story, read
this comic that came with the original game:
http://www.atariage.com/comics/comic_thumbs.html?MagazineID=48


Requirements:
Python 2 or 3, Pygame


How to run:
python game.py


How to play:
Your goal is to destroy the enemy base moving along the right side of the
screen. To do this you must open a hole in its protective shield, collect enough
energy to activate your cannon, and aim the cannon to hit the base.

-Arrow keys to move
-Z or Space to shoot
-Shooting normally fires a small bullet from the player which kills shield cells
-Running into the shield a few times will eat one cell at a time
-Touch the left side of the screen to activate cannon; requires 5 energy
   -Active cannon appears as a rectangle on the left side of the screen
   -Shooting when the cannon is active fires it straight horizontally
   -If the cannon goes offscreen you will need to activate it again
-Get energy by:
   -eating shield cell (1 energy)
   -touching enemy base (2 energy)
   -catching cannon after it bounces off the shield (4 energy)
-Hit the enemy base with the cannon to win the level
-Don't die


Todo:
-proper animations and delays for player death, level end, etc
-proper sprites and title screen
-sounds
-make the game actually fun
   -enemy speed curves
   -improve enemy base transition rate (straight probability sucks)
   -different enemy shields
   -game modes (maybe a beginner's mode like in the original)