There is no ending. I grinded through 15 levels and you didn't even give me a congratulations screen.
The flaws of the AI really become apparent on the last level where you need them to attack specific portals and not just whichever is closer and losing levels from certain attacks is just sadistic, I invested valuable time into sending a high level unit into the field, just to have it stripped away from me by a single attack, simply infuriating.
Why do I lose 10% of my total skill points if I respec? What did I do to you Mr/Ms Developer? What gameplay purpose does punishing respec fulfill aside from "waste all of my time and make me question why I began playing your game in the first place."
This is not challenge. This is asking the player to be smart enough to not send a unit up against a unit of matching type, which doesn't even help anyway as you'll frequently see a melee unit fruitlessly bashing away at a melee enemy and ignoring the other ranged enemies it could easily kill in one blow.
All I ask for is a way to point units at the right targets and not pray that the AI decides to do the smart thing and target things it can actually win against.