We're stalkers, clearly. Cleeeearly. Honestly I just heard this from someone else.
Either way just keep your game on normal (It's not all that hard casually anyhow. I like to keep it there since it's... you know. The game as it is planned to be played normally).
Oh yeah, and Altar Emerald and Nonaggression aren't in boss attack, so make sure you have normal difficulty on when you time attack those since you have to hit the main mode for those. But yeah, it's an easy fix, I'm sure you can get things right next time.