Alien Behaviour Ideas
	=====================

1.	Control points around a level, together with a table of
	'nearest pt in direction of one point from another' values
	can be used for the following purposes:
	
	a.	To give a direction for sounds to come from when a noise
		is made in a remote location.
	
	b.	To give aliens a means of tracking you by sound alone.
		To allow aliens to 'know' their way around and so, in
		later levels, fight more intelligently.

Expansion of ideas:

1b:
	Aliens can 'hear' a noise coming from the nearest point, and
	head towards it. They will remember, until another sound distracts
	them for example, the way they have come, and so not retrace their
	steps. So if they are in a corridor, they will continue until they
	are unsure of which way to go. Then they will either decide to
	guess, or stop and wait for another sound to give them a clue as
	to where you are.
	Levels of difficulty:
		Easiest: The aliens have no memory of where they have been
			 and behave in a purely reactionary fashion; they
			 either have to hear or see something to move, and
			 do not remember the last seen position of the
			 player.
		Hardest:
			The aliens have a good memory for where they have
			been and can decide to guess or wait at crossroads
			or points of uncertainty. If a guess is made and
			a subsequent noise makes them retrace their steps,
			they will continue to the last point of uncertainty
			and make another guess. They can also look ahead to
			the next point of uncertainty, and see if they could
			send another group to the same point via a different
			route.
	
	To make sure the game does not become impossibly hard, it is
	important to balance the intelligence and teamwork of the aliens
	with devastating firepower and the ability of the player to 'fool'
	the aliens into doing things wrong. For example, leaving time-delay
	bombs around will distract them, setting off sirens will draw them
	into killing-grounds (hopefully) and setting pressure mines in
	corridors and then making lots of noise at the other end will blow
	them up as they come charging to attack. Access to the computer will
	become more important tactically, to close doors, activate robot
	or turret sentries and so on. Say you have a large room with two
	dormant turrets, and sealable doors. Careful scrutiny of the
	map via the computer will reveal this fact, and the player could
	arrange to lure a large number of aliens into the room, seal the
	doors and activate the sentries, which would eliminate a good deal
	of the threat. The aliens would also be guarding certain important
	areas such as egg-chambers, and sending in robot attack drones would
	cause marauding aliens to retreat and defend. Certain objectives
	would need to be accomplished before a level could be left
	successfully.
	
Example Mission objectives:

	Retrieve a communications device from the inoperative command centre.
Attract minimum of alien attention and get out as quickly as possible. This
mission could be played in many ways; for example there could be security
zones the player could either try and bypass, obtain clearance through
hacking of a terminal (which happens to have some aliens lurking nearby)
or just plough through, activating the alarms and the robot sentries and
attracting the attention of the aliens, and try to blast a path back to the
exit.

	Clear out a section so medics can get through to attend wounded
people on the other side. First the area must be sealed from further
infestation (By accessing the computer terminals and getting clearance) and
then you must wipe out the aliens already present.

	Act as an escort to some people (Techs or medics or survivors) to
get them out of a section alive. You can tell them where to head for
and try to keep them out of trouble (seal them in rooms so the aliens cant
get at them, then try and clear a path) or just run through as quickly as
possible, blasting away. People might panic and run away; you have to
decide whether to go after them and try and save them, save the rest and
then go back and rescue the others before implantation, or whatever.
Take too long and the aliens will find you and ambush you, killing everyone.

	You might have to seal areas to restrict the movement of aliens
around the ship, by closing and welding shut doors or whatever.

	The alien queen will obviously come into things at the end, and
will be really hard to kill, really clever and able to control things like
doors and so on, so it will be a challenge trying to weaken her with
different tactics before going in for the kill.

Different types of alien will be around; humanoid aliens, four-legged small
but fast types, large and really thick-skinned, and so on. The best way
is to use the kit-form aliens with heads, arms and so on applied seperately.
That way huge numbers of frames are possible (Say 25 frames for running,
special moves for when they are looking around, uncertain of where to head
next), leaping attacks and feasting on victims, dismembered aliens lying
around, injured aliens with arms blown off and screaming defiance.
Aliens can also 'play dead', waiting until your back is turned or you
step too close before attacking.