I've been working on level creation, but level created are nothing like those in Diablo - they're maze of twisty little passages with some rooms. Will have to tweak it.
I was also idly wondering about adding more RPG-like elements in the game, like stats. I know that creating full Diablo (clone? parody?) is out of my reach, even if I would work whole 6 months, but I want to add some things from it - I don't want the game to be boring and for one sitting only. I want to add that something that Diablo had. The 'one more level' factor.
Oh well, enough ranting, back to coding. After I will manage to create good levels, I'll work on adding some more graphics into the game for a while (walls mostly), and then will work on adding random stuff in the rooms.