[feature request] better Single Level experience (as an option)

[axredneck]

Example: "extreme" level size, part of map is "urban-ish" with streets, part of it is "tech-ish", part of is "psichedelic", map begins with weak monsters and ends with boss(es) or with "gotcha", part of map is built of one prefabs, part of other prefabs etc. In other words, different parts of extreme-sized map should look and play differently. (Yes, i'm the person who hates megawads but likes megamaps)