Variety
My brother is in the beta and I've tried it out. I applaud the attention being payed to game balancing, but most of my affectation for this type of game comes from not just the diversity of the abilities and back stories of the Demigods. It also comes from the number of playable characters.
8 characters is too few... everything else in the game is generic anyway. It's pretty much all about the heroes. I dislike being in a game like this where I was forced to play a mirror match against the same character, it would break whatever modicum of immersion I'd nursed into being. I would consider purchasing this game if there were more than 20 playable 'gods'. Devs too obsessed with balancing often end up producing something lacking in strategic complexity and replayability.