Originally Posted by Gragnak
The walls and rusty iron cells could be evil living things.

If well differentiated, 16-20 monster types is sufficient for me, though I support the evil walls idea .
Personally I´m more interested in how significant role traps and puzzles have, this kind of game presents a good opportunity to go nuts with these.
I also hope there´s some non-linearity when it comes to traversing between levels, doesn´t have to be of Chaos Strikes Back grade, but levels being linked with more than one staircase would be nice. In Dungeon Master, freezing the dragon under a pit and then going up one level and falling through that pit was a cool dispatchment possibility.