Alpha 1

1) A new scene

2) Split the original AI into three different AI mode:
a) Melee attack AI: the AI will chase you if you get close, and slow you
down when it is really close.
b) Range attack AI: the AI will throw some "trash" at you. If you are
hit, you will be slowed down. If you get close, it will hide behind the
light pole.
c) Steal AI: pretty much the same as a). But at melee range, it will
steal a book from you every few seconds.

3) Make the AI interactive with the book that the player throws out
a) The first and third AI will be attracted by the book, and leave you
alone.
b) The second one will hide behind the light pole.