This is the most on-topic place where I can post this, so here I go:
Anyone else think it is neat how some megawads like Alien Vendetta, Eternal, and Amdosia have certain levels where the physical appearance of the exit and the physical appearance of the next map's entrance are connected, as if they are one major level? It feels like nice level design that is lacking in the canon Doom games. Amdosia has a lot of that and even 4 or 5 maps connecting physically in this fashion. Then I can try to imagine that right beyond, above, or below the borders of this map is supposed to be the room from the previous map. It also gives me the "I wonder what is beyond this" feel. Especially with no swtich in the exit and you just walk in the door or jump in the pit, and when starting the next map, you can turn around and see that the beginning of the map is suppose to take place just beyond where you exited.
The opposite of this nice level design would be the teleporter exits that were at the end of every map in Plutonia and Plutonia II, which makes the level design less interesting.