Here is a demo for !Pois!.wad that demostrates all the secrets.
This file explains all the secrets for all you guys that can't
learn from visual aids.

****Warning! Doom version 1.666 is REQUIRED to play this demo!
****Warning! !Pois!.wad is REQUIRED to play this demo!

Playing the demo: Doom -file !pois!.wad -playdemo !poisdem

Got it?

O.K. Here is the explaination.

Secret #1: The Super Armor.  Go forward to the first door in the first
room.  Open the door( It is actually a lift.) and get the shotgun.  Walk 
backwards until you are directly on top of where the door was.  Ride the
door up when it closes.  Turn left.  Hey look, some armor, COOL!

Secret #2: That damn 200% life that is staring you in the face, but you
just can't reach.  O.K. go through stone room, where Superlife is.  Go through
the left door, near the lift with a marble face on it. (Below the skull wall...)
Push the button opposite it to open the door.  Don't listen to that blue key
crap.  In the room that follows there are two switches that are next to
each other in the opposite corner of the room, from the enterance.  Push the
right button, once.  Jump into the lava below and there will be a little
square that has raised itself out of the red slime.  On the side of the
square is a button.  Push it.  Walk to the box of ammo.  You will teleport 
back up, near one of those Poison signs.  Push both corner  buttons many times,
until all three platforms are within view and all the same height.  Without
falling off, press SHIFT and run along all the platforms and get the 
chainsaw, etc... When you reach the end, you will teleport.  Push the button
that opens the door and leave.  Notice anything different.  Yes the skulls
don't have blood on them anymore!  Use the lift with a marble face on it
and go up there!  Walk through the skull wall, there will be two closed eyes.
Open them!  Stairs will form and you will be able to get the 200%. Watch
out for the Cacodemons. They don't like it when you figure out the secrets.

Secret #3- The Rocket Launcher.  This is a MONSTER ACTIVATED SECRET.  Go up 
the right lift, from the prison room.  Open the wooden door and push the button.
Kill MOST of the baddies, but leave a few walking around.  Get the yellow key.
(You'll need it later!) It is in the middle of the swirly pool of nasty stuff.  
Pull the switch in that room also, it opens one of the cells, but that isn't 
a secret. Leave Go up the left lift.  Wait for the MONSTER ACTIVATED LIFT to 
lower and go on in.  Look Familiar, well that rocket launcher doesn't!  
Hey, you're back where those Cacodemons were, Cool!

Secret #4- The Chaingun.  Any idiot knows where the chaingun is. But it is 
difficult to get.  Go back to where you got the superlife, but this time
go in the right door, instead of the left.  Kill the guys, push the button.
A Rocket Launcher could be usefull here... (See Above...) Next to the 
enterance , on the left going out is one of those storage containers that
those Cacodemons came out of.  Push the rear wall and Hey, a switch! (You
NEED the yellow key to open that secret door!) Push it, it opens the other
cell, where the chaingun is located.

Well have fun.  Look forward to EYE OF THE BEHOLDER coming 1996.  !Pois!
is the first level. !PIPE! is the second.  I hope you like my masterful
playing on this really nifty PWAD.