I have a few ideas for Dungeons... ((For N@W or Adventure Map))
1: Navy Raid. Foreigners come from distant lands to claim these lands for themselves. Four minor vessels each with a single Cannon flank a Larger vessel with numerous Cannons spread over its different levels are pointed towards the mainland and a known port town. Ready to fire hell and brimstone onto the Town. Warriors are tasked with making aboard the smaller vessels and sabotaging their cannons to misfire before the Fuse Burns and ignites each cannon before making to the larger vessel and finding and sabotaging their cannons. ALL of this to a timer that is activated via a Long Burning Furnace Clock - When the players board each vessel they must place 64 charcoal/coal into a Furnace containing Cobblestone or some longer burning product. When the Furnace finishes cooking the stone it will change state thus causing a redstone torch to activate the cannon...
Foes - Mobs forced Spawned or such. Trapped Rooms. Basic Puzzles. Time itself...
2: Dwarven Trial. Armok has called for your Judgement. And forced alone or with another through a series of Trials from Easy to Difficult Puzzles and Trapped rooms. Alone it will be hard, but with another you must rely on the other at times to get you through a room which is filling with water/magma, but most likely magma. Through out the Trial there is special items to collect, from Iron Bars to Golden Ingots and many temptations for gaining more then the normal when you are asked to care for another life. Sacrifice him for this room may earn you more rewards but doors may not be open to you on the future path and you ally might find it easier to... Fail... his assigned task when you find yourself on the other end...
Foes - Puzzles, Trapped rooms. And if played in Twoplayer Mode. Eachother. And perhaps something else...