Shantae: Half-Genie Hero Ultimate Edition

as the achievement states you must complete a stage without using the sword meaning you must not press the button once. a stage is complete when you reach the end of a section of the level and about to load into the next section you encounter the old guy who gives you the option to save, you can choose to save or not is up to you, but upon entering the next stage the achievement will pop. probably the earliest you can get it is starting a new game and going through that first section of first level (Main Street) or you can wait till either the sliding section the second level just before the boss (Mermaid Falls)