If 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.
 Playstyle challenges
Restrict the way you play the game with self-enforced rules. Only embark with certain items and skills, or restrict your play style in other ways.
 Construction challenges
Try building some
ridiculously humongous, overcomplicated construction, using whatever inappropriate 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.
 Whatever challenges
Do whatever stupid dwarf trick floats your boat.