I don't mean to avoid the squarred level design and ennemy navigation : the player would not have to navigate tile by tile, but freely.
Perhaps keep the fixed combat system : once you encounter an ennemy you can't move and just fight or use the flee option like in old RPGs !
But player Free movement would be lot more cool to quickly look every where and pickup anything.
Lot more fluid and playable for the player.

The towns option would be great to break up the dungeon routine
Somewhat like Diablo 2 game or other indie games, it could be some sort of Torchlight game with one or more towns, but
in Dungeon Master style (combat, puzzles, treasures, etc ...) instead of hack and slash !

Some indie humour remake :

Wizardry series were also big dungeon game style




And i find Greemlock pretty solid.
The ennemies and 3D effects, lightening, dungeon are great.
I just would want more variety like :
-diversified 3D tiles
-different texture walls
-plants
-big places
-equipment sellers with a stand in some points of the dungeon
-some fishing points
-some craft system
-free FPS control for player

Well perhaps i prefer Wizardry in some little different style finally !

Wizardry PS2 Video

The level map and moveent is squarre based, but the 3D is tileset varied going form indoor to outdoor :

Wizardry PS2 video 2

Wizardry 8 on PC with free FPS camera is great, and it keeps the Dungeon combat system and cursor to inspect all thinsg in the level also :

Wizardry 8 PC

Now to make another Dungeon Master style, you need to find original or engaging ideas, because there are already one or two in the indie scene that are great already !

Perhaps ideas like :
- mixing physic puzzles why not ?
- special abilities like jump, dig some walls etc ...
- 3D platform action mixed in with dangerous areas
etc ...

If you put graphical touches and style liek for Superku game,
you could achieve something great and original but in Dungeon Master style .. let's hope you'll begin something in that way