Egg Engines is the sixth level in Kirby's Return to Dream Land.
Egg Engines is the first level of the game to take place on Halcandra, taking place after Kirby and company crash land in the Lor Starcutter on the planet. It a highly-mechanized and industrial area on one of the many plateaus of Halcandra, with most of the terrain covered in metal construction work, machines, and hazardous terrain and structures, reminiscent of planet Mekkai's surroundings. Its skyline is dominated by large buildings and steel girders from end to end, and behind that looms Halcandra's volcano in Dangerous Dinner. The parts Kirby ventures through appear to be a factory of some sort, as they are filled with conveyor belts and moving parts. From its ground sprouts what appears to be living mechanical flowers occasionally. There are no visible residents, and the city looks completely abandoned.
Halcandran equivalents of Planet Popstar's enemies are first introduced within stages in Egg Engines. Most of them are simply of different color, but there are a few curiously different ones, including the Halcandle Dee and Halcandle Armor Dee. Kirby can use Super Abilities to clear the way in some stages, revealing dimensional rifts.
Egg Engines contains six stages. The mid-boss of the first stage is Ice Sphere Doomer, the mid-boss of the second stage is Dubior, the mid-bosses of the third stage are King Doo, Moundo and Ice Sphere Doomer, and the mid-boss of the fourth stage is Kibble Blade. The boss of Egg Engines is Metal General.
Stage 5 contains the game's second hidden HAL room, which detracts from the tradition of a Broom Hatter sweeping the letter "L", and instead has a Halcandle Dee pacing on it. It contains the Whip, Water, Leaf, and Spear Copy Pedestals.
- In the room with the Cannons, when in the cannon above the optional door, shoot when the crusher is closed and enter the optional door. In the optional room, shoot the cannon when the moving wall is about to move.
- Use Monster Flame to light the fuse of the giant Bomb Machine. This will reveal a Dimensional rift zone. Enter the Dimensional rift and defeat the Ice Sphere Doomer at the end.
- Defeat the White Sphere Doomer at the end of the Dimensional rift zone.
- In the room with the screw stalactites, obtain Ice, Parasol, or Water. In the next room, use Ice's Snow Storm, Parasol's water droplets, or Water's Geyser, to destroy the Fire Blocks in the ceiling.
- In the room with the Gigatzos and Volttzos, obtain Stone from Rocky. In the following room, float up into the air pocket and use Stone Smash to destroy the Metal Blocks.
- Use Spark from Dubior to hit the third Bomb Block in the ceiling using Thunderbolt.
- Bring the Key to the lock at the end of the room. Use the blue Ceiling Switch to summon the key, and press another blue Switch later to swap out a spiked platform for a platform lacking spikes.
- In the second room, pull the blue Ceiling Switch that appears after the downward incline.
- In the room after the fight with King Doo & Moundo, press the red Switch and run to the Energy Sphere floating in the gap between the platforms.
- Use Flare Beam to light up all of the light boxes in the second room. The platform will lower and reveal a passage to the right where the Dimensional rift zone is hidden, Enter the Dimensional rift zone and defeat the White Sphere Doomer at the end.
- Defeat the Ice Sphere Doomer at the end of the Dimensional rift zone.
- In the dark room, destroy the stone blocks above the Swordory and obtain Hammer from the Copy Essence. After descending, go to the right, drop the candle, and use the hammer to destroy the Metal Blocks.
- Near the end of the dark room, pass the Clayn that's in front of the exit door and continue to the left, destroying the stone blocks in the way.
- Obtain Cutter from Kibble Blade, and throw a left-facing Cutter Boomerang, aimed upward slightly in order to hit the blue Switch at the other side of the waterfall.
- After leaving the alcove with the two Barracus, swim down instead of following the Stars.
- In the room with the giant Barbars, swim into the optional room periodically obscured by a Barbar. In the dark room, obtain Spark from the Sparky. Use Thunderbolt to destroy a Bomb Block and grab the Candle; use the candle to find the Key. Use Thunderbolt to destroy the Bomb Block to drop the Key. Discard the Candle and pick up the Key and bring it to the lock.
- In the first crusher room, appears in a left alcove.
- In the room with the treadmills, enter the optional room obscured by the Halcandle Armor Dee. Grab the Key and toss it onto the treadmill and quickly make it to the right before it falls. Alternatively, the player can get on the treadmill while holding the Key and crouch in order to avoid the Gordos.
- In the second crusher room, float in the middle when the ceiling falls for the third time.
- Use the Invisibility Stone to get through the second crystal wall. Pull the blue Ceiling Switch to open the gate.
- In the third crusher room, appears near the end.
- One tune heard in dark rooms contains part of the mid-boss theme from Kirby 64: The Crystal Shards. Another track heard in Stage 4 contains the music from Stage 6 of Iceberg in Kirby's Dream Land 3, as well as 0²'s theme from Kirby 64: The Crystal Shards.
- The themes for Stage 2 were reused in Kirby: Triple Deluxe.
- The music for Stage 3 was recycled in Kirby: Triple Deluxe as one of the songs for the extra stage of Wild World.
- Stage 5 of Egg Engines is the only stage in Halcandra to not have a mid-boss.
- In Kirby Star Allies, when playing the Guest Star ???? Star Allies Go! sub-game as Magolor, some stage layout in Level 5 is changed to reflect Stage 3 of Dangerous Dinner from Kirby's Return to Dream Land. The "dimensional rift sequence" replicates some layout from Stage 5 of Egg Engines (despite that portion being on Halcandra, not inside a rift), and the Sphere Doomers are represented by a Bronto Burt Room Guarder and Twin Vividria.