|This article is about the current version of DF.|
If "vanilla" Dwarf Fortress wasn't difficult enough for you, consider challenges. Challenges can make the game harder, or just give you an objective to strive for.
Restrict the way you play the game with self-enforced rules. Only embark with certain items and skills, or restrict your playstyle in other ways.
Try building some ridiculously humongous, complicated construction, using whatever appropriate building method your fevered imagination can come up with! Need some ideas? Take a look at the megaprojects page! See the mega construction page for tips and tricks related to constructing megaprojects.
Do whatever stupid dwarf trick floats your boat.