There are a lot of replies here, so I apologize if there is duplication as I don't really want to read all of them...
I managed to make it through the battle, but when I finished it felt more like it was luck. The biggest problem I had was I left the tutorial feeling pretty confident about how to do battle, but then couldn't figure out how to keep Graham in the boat. I'm still not sure exactly what kept him in the boat, because I just kept clicking randomly on anything that seemed to keep him in the boat. I couldn't anticipate all of Shadrack's moves, but most left enough time for me to dodge after he started, so the extra time was greatly appreciated. I was a bit surprised to see such a difference in gameplay, but in an adventure, anything can happen! I found the previous action scenes allowed me to feel more comfortable with this type of scene. If I was having a bad day, I think my tolerance of the battle would have been diminished, as I usually play action games on easy so I can feel like a true hero as I obliterate my foes.