About at the monolith boss... My frustrations with this game are growing, am I under leveled?

My characters are low to mid 40s at the monolith. A single fight against small enemies takes me about 20-30 minutes and uses all my revive potions. I can't dodge or repel most of the time. My friend is telling me it should not be this difficult. I don't think I'm particularly bad at rhythm games, my coordination is fine. I just can't get the choreography down at all.

What level should I be for this area?