The player controls Kirby in an adventure through the titular forgotten land to rescue Waddle Dees kidnapped by the ferocious Beast Pack.

To complete each stage to save the Waddle Dees, Kirby can use a wide range of copy abilities to help battle enemies and progress.

Kirby and the Forgotten Land was well received by critics, praising its graphics, level design, gameplay, soundtrack, and amount of content, with some calling it among the best games in the series.

Among them include fishing, working a part-time job at Waddle Dee Café, and a puzzle minigame akin to Kirby Tilt 'n' Tumble.

Kirby is among those sucked into the vortex and finds himself in an abandoned civilization informally called the "new world," where he discovers that the Waddle Dees from Dream Land are being kidnapped by the native wildlife, the Beast Pack.

By destroying a hypnotic mask that Dedede was wearing, Kirby frees him from the Beast Pack's control, then ascends into their center of operations, Lab Discovera, to find Elfilin.

Leongar explains that the previous inhabitants of the new world used ID-F86's power to depart for "a land of dreams," and that he intends to do the same by reuniting Fecto Forgo with Elfilin.

They also opened vortices to Dream Land, using the Beast Pack to hypnotize King Dedede and kidnap the Waddle Dees for labor, in order to resume their invasion.

Kirby narrowly defeats Fecto Elfilis by ramming a semi-trailer truck into them; he and Elfilin then find themselves back in Dream Land, where the vortex is still open.

Clawroline, a member of the Beast Pack and friend of Leongar, discovers a rift in Waddle Dee Town that leads to Forgo Dreams.

In an optional final encounter, Kirby combats the phantoms of Forgo Dreams in a boss rush before confronting the newly formed Chaos Elfilis.

Kamiyama ultimately created a detailed pitch for a 3D Kirby game that presented solutions to the issues that HAL Laboratory had faced, including character design, gameplay and many other aspects, finally allowing for development to begin on a 3D title.

[17][18][19] Early on, play testers at Nintendo felt that the wide 3D environments made gameplay too easy as players could simply step away from enemy attacks.

They suggested that enemy density be increased, but HAL Laboratory declined, saying they did not want to "torment" Kirby or prevent players from peacefully exploring the game world.

The upgradable copy abilities and Mouthful Mode were also heavily praised for the gameplay variety they provided while remaining a part of the game's core design, making the combat and platforming consistently interesting as a result.

Boss fights were also lauded for requiring the utilization of copy abilities, with several praising the increased difficulty of Forgotten Land in comparison to previous entries in the franchise.

[49][50] Minor criticism was directed towards the movement of Kirby for feeling limited and "sluggish",[33] grounded environments,[37] and the recurring mini-bosses that some found stale.