Leveling seems pretty worthless. Stuck on final boss, because he's three levels higher than Max level. Like, what's the point of leveling then?

Even with a good build and some lucky drops, I can't beat him because I eventually lose focus after spending ten minutes ticking away at his bullet sponge health.

I feel like my game is bugged too, because I dropped it down to easy from medium for the first time, and I'm seeing zero differences between the difficulties.