I was unable to understand if I hit an enemy or not, or if a character in game is a friend or an enemy.
For example, in the stage where is this mage who is spawning those little enemies, I thought that this guy was a good guy and enemies are just spawning in this area and avoid them all together.
When I was to the dragon even with, 8000 energy, I failed to beat him because I was unable to understand if I hit him or not and this was my game over.