My group of friends have now played almost a few dozen games of Dungeon! and we have consistently noticed that the Cleric wins.
The Cleric has a target of 10,000 and works very well across all levels till level 4.
The Rogue has a small target too, but it cannot perform very well beyond level 3.
The Fighter has a larger target of 20,000, but can perform as well as the Cleric (till about level 4). It gets difficult in level 5 or 6.
The Wizard has a very high target of 30,000, so its best bet is level 5 or 6 to gain a lot of treasure very fast.
So I am not sure if the game is biased towards the Cleric - any thoughts?