The stage is significantly longer than the one it replaces. Instead of a room with a Parasol Waddle Dee, a Rocky, a Waddle Doo and a Poppy Bros. Jr., and a door leading to the battle ring, it consists of separate rooms that were designed to finish off Kirby. Kirby must navigate his way through hallways and rooms with the mid-bosses that he had fought in the first three levels (albeit with a different color scheme). After King Dedede has thrown all of his "servants" at Kirby, Kirby must fight Dedede's right handWaddle Dee, who is wearing a bandana and has ridiculously high stamina (he can still be inhaled, however, thus defeating him in one hit). Dedede then guides Kirby to his ring, which now has an electric fence around it, and only one spectator (Bandana Waddle Dee), where he offers Kirby a hammer and reveals his secret weapon.
Kirby defeats Dedede, and sends him flying out of his castle again. King Dedede then decides to travel through the desert he landed on, but not without some friends—he is accompanied by some Waddle Dees (including Bandana Waddle Dee).
The stage makes use of music from Revenge of Meta Knight which plays during sequences within the Halberd's interior. When fighting King Dedede, the "Masked Dedede" theme plays. This is the only instance of the theme in the game.
The musical motif is recurrent throughout many games and is not limited to contexts involving Dedede directly. The only notable confrontation against Dedede where some variation of the theme does not play is in Kirby's Adventure, when fighting him at the Fountain of Dreams.
Kirby Super Star introduces an extended version of the theme music, which has been used ever since.