The achievement is self explanatory, but here's some tips to help make the game easier:
+ Learn your combos! Each weapon has it's own combos, and if you learn to use them, you'll dish out a lot more damage! This game can be played like a buttonmasher, but it isn't one!
+ Don't forget that you can heal! If things get rough, press your back button and eat something to get your health back! Only use continue hearts when your heart is empty, as each new one refills the entire thing instead of just 1/4th of it.
+ As soon as you get the Amulets, you can use a second controller or a guitar to jump into the action! This second player can die an infinite amount of times without you losing the level, take advantage of this! (you can put a rubber band on your controllers right analog stick and warp up into a corner, making yourself invincible while you whip out controller 2 and kill everything, dying as many times as you have to.)
+ Every boss and every enemy has a strategy or a combo that is insanely effective against it. Practice makes perfect!