Just played the game about a week ago, and it felt very solid. Did not play the whole thing, but I cleared the bandits cave, and finished the first section of the main dungeon. Also, I only played as a simple warrior, and probably might miss some cool features. The game felt well balanced.
I liked the bandits' cave generator, but not that much the Temple's dungeon generator, which has a lot of unnecessary doors and duplicating hallways. Maybe, it can be improved.
1. Since there are many character classes, it may be intersting to see mobs who belong to those classes. They may be enemies, or allies. It makes the player become intersted in trying those other classes. You free a paladin from a prison or cage, and you together find the way from the dungeon. Or you have to defeat a sorcerer, and to do so you may seek help from another sorcerer sitting somewhere in a hut in the overworld map. Alternatively, you may find sorcerer's family member or his loved one, who will convince the sorcerer to give up his evil ways.
2. New characters may be unlocked gradualy. You may have to defeat such a character, or find an ally who belongs to this class, or do a quest that, for example, makes a druids sect move to the town, etc.
3. Some other random thoughts: It may be intersting to see mechanisms in the dungeons. Levers opening doors, lava rivers, a mob-producing factory (making iron golems, for example).
4. Collective mobs behavior (for example, when mobs run away if you kill one of them - the type of thing the Fallen Ones do in Diablo II).
The game's quest system is great, you don't see such things very often in RLs and other indie/free games, but it's a great thing. The game is very Diablo influenced. Not sure is it good or bad, but it is quite amuzing that you can finally save the guy who is dying at the Temple's entrance.. )
A few more ideas:
5. Maybe, you may try to give the player more choice. Playing as a warrior class, my only tactical decisions were about trying to face only one enemy at a time. And always go to corridors to dispatch them one by one if they are in a group.
6. The time system can be improved. It feels that at the moment, all mobs have speed either 100%, or 200% (hounds). Some variety may make the game more tactical. It also gives more choice in picking your equipment.
Still, very solid game. I don't want to sound like I'm criticising it. It is immersive and you really get the atmosphere thanks to the dialogs and the quests, it's a huge plus. I think, it's good to add a new quest immediately after finishing the first section of the main dungeon, so the player gets a new big incentive for going deeper into the dungeon.