I found Act I not harsh but full of frustating elements. Traps in piss you off locations, 90% of flying enemies who dodge and are tanky for some reason. Like that one particular fly which spawns in exact precise location in runback to boss for you to collide, unless you are sprinting. Bullshit like this.

Act II get's better as you unlock more movement and the lore develops. There is some unique stuff there. Boses are also fine for me, random summons are annoying but that's what you have tools for, kill them immediatelly.