Bandana Waddle Dee, King Dedede, and Meta Knight can all be unlocked as Dream Friends through progression in Story Mode.

[5] On the Jambandra space station far away from Kirby's home Planet Popstar, a dark crystal heart explodes due to an imperfection in a mysterious ritual, sending its numerous fragments, Jamba Hearts, hurtling into deep space.

Many characters, including King Dedede and Meta Knight, are possessed while investigating the dark hearts that land on Popstar.

Kirby notices many Waddle Dees bringing food to Castle Dedede and decides to investigate.

After Kirby defeats Meta Knight and King Dedede and frees them from the Jamba Heart's influence, a large fortress known as the Jambastion lands on Popstar.

After defeating the Three Mage-Sisters, a trio composed of Francisca, Flamberge, and Zan Partizanne, Kirby and his friends fly to the far reaches of space.

They battle Zan once again before meeting Hyness, an evil cleric who is planning to restore a dark force, Void Termina, to full power using the Jamba Hearts.

Kirby then destroys Void Termina with the Star Allies Sparkler, summoning friends in the process.

The Sparkler is destroyed by the resulting explosion, but Kirby uses a Warp Star to return himself and his friends safely home.

[11] HAL Laboratory developer Shinya Kumazaki went over the world map concept, and the ability of creating more open, higher resolution imagery with the Nintendo Switch console.

[12] The idea for the downloadable content was to help give attention to past Kirby games, and the series as a whole.

[15][18][21] Mitch Vogel from Nintendo Life called the visuals "top notch", but yearned for a more distinctive design.

[21] Destructoid reviewer Chris Carter praised the "gorgeous rendered backgrounds", and stated how recruiting enemies to your team "goes beyond an adorable gimmick.

[18] Brendan Graeber from IGN liked the layer of strategy and the concept of re-arranging the friends for different puzzle solutions.

[32] The 2023 CESA Games White Papers revealed that Kirby Star Allies has sold 4.38 million copies, as of December 31, 2022.