Well, its a good timekiller, but a few things prevented it form becoming more than that.
1: While the idea of unlocking the story as you play is awesome, the execution of the idea wasn't as good as it could have been. It was basically people got mad attacked and died over and over again. I personally think it would be cool if you made a sequel where the story was a mystery for the player to solve as he/she played.
2: The distribution of experience was very flat while the cost of spells went up. For example, I would get more experience for getting the, lets say around 50 souls on level 1 than for getting several hundred souls on a later level.
3: You cant replay levels, which is good because of the exp. distribution, but bad overall. If the player wants to replay a level, they have to restart the game.
A few changes to this would change it from a time waster to a really good game.