Most of these levels have a main, center room that can be easily identified., usualy circular or square in shape.

I don't think this is unique to ep 3. Fredrik 18:38, 5 April 2007 (UTC)

I agree with Fredrik. I dont think this sentence is true at all. Only for E3M7, E3M8 is that really true. For the other levels, sure there may be one area that is larger than the others but it is not necessarily central. A level designer can design a Doom level to be any shape at all, and I dont believe there is much commonality in episode 3 apart from the textures due to the 3rd episode being set in Hell. I would remove this sentence on grounds of accuracy. I believe also that E3M6 (Mt Erebus) was the first Doom level where a level designer realised that the level could be entirely "outdoors".

Comparing to other Megawads: PLUTONIA - has a consistent teleport pad where each level ends ICARUS - has a consistent "space exit" where each level ends. But thematically the WAD starts up space age and by level 20 is very differnt in style. ETERNAL - very consistent in terms of overall style.

But I have noticed that some Megawads are not overall consistent with a lot of variations between levels.

Returning back to Doom, E1M1 -> E1M7, E1M9 are very consistent, all tech based. After that, variation increases. IDLover 19:31, 5 April 2007 (UTC)