Developer: The runner must have a shadow. I couldn't stop thinking about it, and wasn't able to finish 15 levels because of the absurdity of not having a shadow. Couldn't stop thinking about it after level 3
A large portion of the game is waiting for animations to start/end (like when a turn is over, before attacks, moving, etc.)
A lot of time is wasted when absolutely nothing is happening. The game is really slow, otherwise it'd be fun.