Spent 60$ in Diablo III and i played it less than this, great game!
Lv: 56+ Warrior,
Here's my feedback:
I would say difficulty progression, at later levels you can go trough all the dungeons without loosing any health and then dying 10 times in less than a second to Demons.
The problem is the Demons all attack at the same time, so if there are 50+ demons (It happens lol) then they all attack at exactly the same time.
After you beat the game once, it says it will become harder, but the difficulty is really low, i would say Buff every dungeon like 300% or more every time you rescue the princess, but fix the demons so they don't attack at the same time, it would be cool to have God Bosses or something, and more Heroic Items Green and higher than green, especially shields! there's no Heroic Shield!
Thanks for the great game!