[Wii] Super Ghouls n' Ghosts

So, I downloaded this one on Virtual Console a few weeks back, and I'm 99% done. However, I do not foresee myself surmounting this landmark anytime soon.

Let me ask the populace: has ANYONE here ever beaten this game? I'm at the last real level, and I can get myself all geared up for the boss; Gold Armor, Goddess Bracelet, Sun Shield, ka-pow! But, the asshole is impossible to fucking beat with the shitty-ass endgame weapon you're forced to use.

It's frustrating as hell.