the 2D version was also significantly more difficult.
*You couldn't farm at all during the winter, which meant that unless you were fast you would get no farming at all for the first year.
*The magma was very far from the surface, which made it a stratigic desision to build an infrastructure early or late. Build early and your workers can quickly access your farms, but often cancel for lunch before they even reach the forges, build late and the food from the farms will often rot before it makes it all the way into the fortress.
*If you dug something out, you couldn't refill it. A single misdug tile would horribly mess up any large digging project. Sure you could block it with a door, but a tantrumming dwarf could destroy the door at an inopportune moment.
* There were permafloods, if an artificial water flood struck a natural water source it would become permanent with no reasonable way to remove it. Many players actually put emergency channels around their fortress for that reason even when they were nowhere near water.
* The cave river flooded every year washing dwarves anywhere near it downriver. Particularly dangerous since there was no way around the cave river. You were REQUIRED to build a bridge over it. And anybody crossing it was at risk. There was no swimming skill. It was so dangerous that there were multiple designs to reduce casualty counts with specially designed bridge systems. But even those weren't 100% safety.
* The cave river, chasm, and lava river spawned critters in ambush mode, often large groups. While the critters themselves weren't very powerful, like the cave river you were required to build a bridge over them, and civilian traffic was often heavy. You needed to either micromanage your militarty to always have soldiers guarding the features or accept a few civilian casualties every now and then. Wells would also have a side effect of spawning cave river creatures.
* Adamantine was forbidden. if you dug even a single tile of it your fortress would be instantly destroyed by demons. No chance to defend yourself the balor was just too powerful. For every tile of adamantine you mined, it would increase your chance of it happening each year by 1% Considering how much adamantine is needed to make even small objects it was very prohibitive. Not to mention the fact that you would encounter the current HFS demon attack LONG before you got anywhere near the stuff with no warning, if you are digging past the magma you WILL hit a demon pit. And unlike now you could not forbid burning stuff.
* No forbidding objects. If there was a sock in the middle of a goblin seige you can bet your dwarves will charge singlemindedly at it. And there wasn't a damn thing you could do other than hope they don't get shot while entrance dancing.