Here are all of my ideas for a dessert type world, if bast were to make one:
Race: human(for now)
Atmosphere: 2.5 million
Salt flats: Every good dessert has salt flats. Since bast is trying to implement multiple terrain types, this could be one of them. The flats would be generated randomly like rivers. The player would have to build salt mines in order to mine salt, and these mines would only be place-able on the salt flat tiles. Regular units would be able to walk on the salt flat tiles as well, it would just be a good decoration and serve as the designated salt mine area.
Salt: Salt in the dessert has many purposes. Since it almost never rains in the dessert, salt can be used as a building material, and it is actually used in real life to build houses in some dessert villages around the world where it never rains. On all other planets, however, salt would obviously be involved with food production. You could change the food processing plant to require small but constant amounts of salt along with sugar to produce massive amounts of food. Bast could also enable non-dessert colonies to produce small amounts of salt by implementing desalination plants that need to be placed next to a river and would produce clean water and tiny amounts of salt. Salt is also used in cattle fields, since cows don't usually get a good amount of electrolytes from eating grass. So if livestock farms were added, salt could play a role in maintaining them.
Alien fruit Cacti: In the dessert planets, cacti would prove to be a viable source of wood/fiber and food. Cacti isn't really wooden, but lets say that there are alien cacti that are hard enough to be a substitute for wood and it's fibers could be woven into ropes. The problem is that cacti grow incredibly slow, so the player would have to be more frugal with their wood supplies than in forest environments. The player can place individual cacti using a dessert rover, albeit with a very high cost to water, and no trees or tree farms are allowed on this map, since the soil is too arid, no matter how advanced the colony becomes. The player would be able to build farms that cultivate cacti for food and wood, but these farms would be very slow at producing both, which means that the player would have to save a very wide area for these farms in order to support an early stage colony. Later in the game, the player should be given acccess to a mega cactus farm
Oil deposits: lot's of oil can be found under the dessert.
Ore: ore is obtained via charcoal compactors, the same as on the forest world.
gold: gold will be obtainable earlier in the game. gold mines are made from wood and salt and would allow the player to generate and store gold earlier in the game than ore. The gold can be used earlier in the game, in combination with wood and salt, to make basic entertainment, research, economic, and governmental structures used for forming a small community without ore. Once ore production is stabilized, these buildings can be upgraded to their regular forms.
immigration: I would implement a rudimentary landing zone that is basically a symbal marked in the ground for landing. It would produce one colonist for every 2 colonists produced by a regular landing pad, but it wouldn't require any power.
Gameplay: Salt and cactus fibers(wood) would be used to make the most basic structures in the dessert environment, and the need for the cactus fibers would prove to be a big hindrance at the beginning of the game until the player builds enough fruit cactus farms to produce a good amount of wood. The player would have to create tons of wells in order to produce enough water to support their colonists and operate the many cactus farms that will need to be built. Wells, in turn, require wood and salt to build. Salt has a small storage cap at first, and salt storage buildings also require wood, water, and salt to build, so you can see how the bottleneck would work if bast were to implement these ideas. Once the player gains an extra 300 wood, they will be able to built the usual charcoal hut, and then a charcoal burner to provid for more power once they get more wood and charcoal. From there, the gameplay is almost identical to the forest map aside from there being no tree farms or trees available for building. Basically, the player would have a long time to wait before they can produce ore, and by the time that the player gains ore production, they will have built an entire community out of salt blocks, gold, and cactus fibers. Bast might also want to add an entertainment building made out of wood and salt so that citizens can still be satisfied during the long wait for ore.
Advantages to map: The most outstanding advantages of the dessert map would be a local supply of oil and salt, but the biggest is the ability to gain gold, research, and civics earlier in the game. Wood storage will be higher on this map since every cactus fruit farm will add to food and wood storage, and so would the mega cactus farm.
Disadvantages: It will be hard to feed and quench your colonists near the beginning of the game. Wood will be scarce for a long time because it grows slow and you will need it to make ore and build important beginning structures. Water is inherently scarce and will be needed to make certain important structures and to keep colonists alive. Salt will have a small cap, so having a big enough supply to make a bunch of buildings at any given point will be hard to do until you manage to build a bunch of salt depots. All in all a very slow growing map.
I hope you all enjoy this idea and please vote for it to be put in the game if you like the ideas. Hopefully bast does decide to implement a dessert planet for at least one of the races, even if he doesn't implement all of the ideas that I've included here.