I'd like to say thanks to everyone who has downloaded my DOOM levels. The 
DOOM Zoo is my 4th WAD file to date and hopefully the best. The only reason 
that I made this level E2M1, is I like the sky colors. It worked real well 
with the outside areas. I also achieved a bizzare effect in the tunnels that 
are outside. This was by accident, but I liked it so much, I left it in. The 
vine patterns seem to be all around you. I would suggest staying close to the 
walls and shoot towards the sound of the monsters, because you won't see them 
until they're right next to you. Also, the door that leads to the exit has to 
be opened by crossing a specific line somewhere in the level. I think this is 
more challenging than a key door. So, if the door won't open, keep looking.
It does work.