Hard agree with agitodev. Text getting obscured by the character sprite on the textboxes is particularly frustrating when trying to figure out how to play.
Why are the items in the equipment slots blinking in and out?
Holding (not dragging) right click to pan around the upgrade tree is very counterintuitive.
What's with the weird numbers in the skill tree? +0.0193% Efficiency? x0.00274 Attack?
In the nicest way possible, I feel like this game is doing a lot of things to try and be different which is not in itself bad, but most of them don't really have the intended effect, or even detract from the experience.