TODO Before release:
====================

	general -- fix laser collision detection.
		add detection of shields
		add detection of friend
		properly handle when multiple collision objects
			on screen at once

	door explosions should be cropped

	when calculating room calcs, take Y position into account
	
	L1 -- fix beast ending
	L1 -- have beast collapse
	L1 -- fix slugs
		+ slugs on ceiling drop
		+ adjust slug attack range
		+ spawn new slugs in 2nd room
		+ be sure can jump over slugs

	L2 -- add doors
	L2 -- disable door/powerline by shooting wall
	L2 -- add aliens
	L2 -- add minimal friend AI
	L2 -- add way to leave L2 to L3
		-- on cart screen, cart is still there at edge of screen?
		+ Implement end scene

	L5 -- add ending scenes?
		Show some pictures
		Do ending
		Play music?

	intro -- add music?



BEHAVIOR DIFFERENCES:
=====================

+ General differences
	* physicist behavior:
		- should be separate sprites for left/right
		  (not one flipped sprite)
		- actual game has much more variety of movement positions
		- if have gun, should be visible when running.  Hard to do
		  this in a way that looks right

	* alien guard behavior:
		- will punch you if you get too close
		- l4, if you draw gun (but not fire) guard won't shoot you,
		  but instead will yell at you a bit

	* gun behavior:
		- doors/walls should explode outward away from blast
		  *unless* there is another door/wall behind it
		- laser should show sparks when hits shields/walls
		- shield cannot be placed if room/floor wrong
		- shield collapse animation if blown up with blast

	* door behavior:
		- blasted doors, the remains appear partly in front


+ Level/Checkpoint 1

	* underwater:
		- underwater in game there is a subtle water-motion effect
		- bubble motion is fancier in real thing

	* by the pool:
		- get out of water, you face forward unless key pressed
		  (we don't have a forward sprite as it looks weird)
		- arrival, the beast movement seems to depend on your xpos?
		- small things like birds flying are not implemented

	* caverns:
		- beast on hill and 2nd screen -- complex, only appears if
		  you happen to leave same time beast does?  then movement
		  depends on xposition?
		- sometimes falling rocks can follow you to next screen

	* rope:
		- earthquake should happen while on rope

	* beast:
		- beast can/should trip and fall if it gets too close but
			then you pull away
		- beast should climb hill in rope room better



+ Level/Checkpoint 2

	* cage room:
		- in game, after some time the guard calms down

	* jail:
		- in actual game, foreground animations can continue
		  to next screen?
		- flashes on wall from gunfire in neighboring room

	* level end:
		- you should fall/scroll halfway down the shaft, then roll
		  a bit before falling into L3

	* Elevator:
		- should be able to change elevator direction mid-floor
		- Elevator should shoot sparks every 20 frames or so

	* View:
		- does music play when looking at city?
		  Not original Amiga version

+ Level/Checkpoint #3:
	* Actual game shakes the camera when you hit the ground after falling

+ Level/Checkpoint #4:
	* Implement guard (shooting, taunting)


KNOWN BUGS:
===========

+ ootw: pool monster grabs you a edge of pool (glitch)
+ intro: there's still a bit of a pause when the elevator door finishes opening
+ running: Missing one running frame (?)


FUTURE WORK:
============
* sprites_to_draw:
  + physicist run+jumping
  + physicist swimming
  + beast tripping
  + alien running
  + friend walking
  + friend running
  + alien punching animation

* L1 pool
  + adjust tentacle to not go off edge of screen
  + adjust x position of tentacle grab

Level/Checkpoint #5:
 + Allow falling into first pit