Here is a world that I finally got after a messing with worldgen for a long time.
It is a hellish world covered mostly in sand desert, with lots of small mountain ranges, apparently no rivers (but there are aquifers plenty), and a good bit of volcanism. All human civilizations exist in round oasis areas surrounded by desert and evil/terrifying areas which make up the majority of the map... each area has two or three pathetic little human cities struggling for survival. ON the map I made with this, there was one oasis area that had only two or three ruins connected by roads.
I had to set the number of civs low, to like 27 or something, in order to get a map, because otherwise the parameters simply could not support more civs. Probably someone with a more powerful computer could get it to gen a world with more civilizations... if they are patient enough.
The goblins and kobolds mostly rule the map. The world made it all the way into the 800s I think before 95% of all megabeasts died off, so that should leave some around to have fun with.
In short, it seems to be a pretty un-diverse, miserable place to live, but it might be fun to adv. mode or even fortress mode if you are sadistic.
Maybe someone who is better at tweaking worldgen can improve a bit on this?
[WORLD_GEN]
[TITLE:Hell World]
[DIM:257:257]
[END_YEAR:1500]
[BEAST_END_YEAR:300:95]
[END_YEAR:1500]
[REVEAL_ALL_HISTORY:1]
[CULL_HISTORICAL_FIGURES:1]
[ELEVATION:15:400:1000:1000]
[RAINFALL:0:45:50:50]
[TEMPERATURE:50:100:50:50]
[DRAINAGE:0:55:50:50]
[VOLCANISM:20:100:0:0]
[SAVAGERY:45:100:400:400]
[ELEVATION_FREQUENCY:5:300:2500:1:1:1250]
[RAIN_FREQUENCY:6:2500:1:1:1:300]
[DRAINAGE_FREQUENCY:6:2500:1:25:100:25]
[TEMPERATURE_FREQUENCY:1:0:0:200:2500:5000]
[SAVAGERY_FREQUENCY:2:50:200:500:1500:4000]
[VOLCANISM_FREQUENCY:6:1:50:100:200:1000]
[GOOD_SQ_COUNTS:1:1:11]
[EVIL_SQ_COUNTS:2500:5000:8000]
[PEAK_NUMBER_MIN:50]
[OCEAN_EDGE_MIN:0]
[VOLCANO_MIN:35]
[REGION_COUNTS:SWAMP:0:0:0]
[REGION_COUNTS:DESERT:0:0:0]
[REGION_COUNTS:FOREST:0:0:0]
[REGION_COUNTS:MOUNTAINS:0:0:0]
[REGION_COUNTS:OCEAN:0:0:0]
[REGION_COUNTS:GLACIER:0:0:0]
[REGION_COUNTS:TUNDRA:0:0:0]
[REGION_COUNTS:GRASSLAND:0:0:0]
[REGION_COUNTS:HILLS:0:0:0]
[EROSION_CYCLE_COUNT:200]
[RIVER_MINS:0:0]
[PERIODICALLY_ERODE_EXTREMES:1]
[OROGRAPHIC_PRECIPITATION:1]
[SUBREGION_MAX:4000]
[CAVE_MAX_SIZE:20]
[MOUNTAIN_CAVE_MIN:190]
[NON_MOUNTAIN_CAVE_MIN:190]
[ALL_CAVES_VISIBLE:0]
[TOTAL_CIV_NUMBER:26]
[TOTAL_CIV_POPULATION:20000]
[PLAYABLE_CIVILIZATION_REQUIRED:1]
[ELEVATION_RANGES:0:0:0]
[RAIN_RANGES:0:0:0]
[DRAINAGE_RANGES:0:0:0]
[SAVAGERY_RANGES:0:0:0]
[VOLCANISM_RANGES:0:0:0]