Currently i reached level 5 with my Characters (and finished the main Alpha quest). All i can say so far is: a mage with 50 Skill Points is able to deal lot more damage than a Ranger or a poor Warrior.

Even with Mana or "On SpeelUsage per Sleep", this wouldn't change, because most of the enemies are "one hit wonders". With Flares and Ligthing at level 13, you deal way more damage then any other melee attack (known to me)

There are two things, who seemes strange or "subject to change":
  • Mages have lot more skills to learn/use
  • every point in intelligence leads to more an additional skillpoint with the next level.