I did it blind and figured out most of it. Even the things I died to I got how they worked. I think if you actually look at your surroundings the mechanics are actually obvious. You are expected to use your knowledge from previous fights to understand this.

The final boss took me several runs to fully understand and it was because I did not observe my surroundings closely, such as the number of eyes on each enemy as it marched.

The reason why it's suitable for casual play is because even if it's too difficult for a casual player, there are up to 23 people available to resurrect them and that's the only reason they will allow mechanics to kill you in one hit. You are even given a chance so on most of the mechanics, the first mistake doesn't kill you but the second one does.