In this sub-game's intro, Kirby is seen taking a walk- but he accidentally falls through a hole. He ventures through what seems to be a cave, and must escape. Throughout the sub-game, he has the option of collecting Treasure Chestitems. Each treasure has a value in Gold, which is also the player's score. 100G (100 gold) is equivalent to 1 USD - this is found in the Dime and 100-Dollar Coin items, which are worth 10G and 10,000G, respectively. The Great Cave Offensive's more adventure-based layout makes it somewhat unique within the classic Kirby series.
As Kirby, the player walks through an environment that resembles a cave. There are a total of sixty treasures strewn throughout the cave. There are Save Cottages in every region which contain a pad to Kirby's progress, and special rooms before a boss fights which contain Copy Essences and a Maxim Tomato. The player traverses the regions in sequence; a forested area (Sub-Tree Area), a lake (Crystal Area), a castle (Old Tower), and a garden (Garden Area). Most are guarded by a boss - the bosses are unique to this game (including the Active-Battle System-based computer boss called Computer Virus).
Gathering treasure is the main objective and the source of difficulty in The Great Cave Offensive. In general, more treasures are hidden in obscure places and are more difficult to obtain in later regions, while the hidden treasures are worth more in Gold. Many of the treasures make references to other notable franchises through their appearance or names.
The oval coin seen on the item screen is a Koban, an ancient Japanese gold coin and bears resemblance to the coin on the head of a Meowth. These coins also feature prominently in the Goemon game series by Konami.
Whip (En) Indy Whip (Jp)
Commonly misinterpreted as a reference to Konami's Castlevania video game series, the Japanese name of this treasure is more revealing: It is in fact the whip of the movie character Indiana Jones, identified as "Indy Whip."
A reference to various RPGs of the Famicom and Super Famicom era, but most closely resembles the Crystal Ball in the Famicom version of Ys: Vanished - Omen.
The white cat seen on the item screen is a common Japanese luck charm, the Maneki Neko.
Seiryu is an azure dragon from Chinese mythology who represents the season of spring and the eastern direction.
The Screw Attack (incorrectly labeled as Screw Ball in Kirby Super Star) is a power-up item in the Metroid video game series that allows the player to perform a jumping attack.
Echigo (越後国) is the name of a place in old Japan currently part of the Niigata Prefecture. Because of the close pronunciation to ichigo (苺), meaning strawberry, this item is sometimes misinterpreted as strawberry candy.
Known as a Senryobako in Japanese, this is specifically a type of box that was used to transport Tokugawa coinage in feudal-era Japan, and was designed to hold an amount of Koban totaling 1000 ryo. This sum is reflected in the box's in-game score value.
Called "Tsuki no Ukifune" (Floating Moon Boat) in Japanese. It clearly has a moon for a sail.
Gold Watering Can
The Gold Watering Can is a hidden item in the Animal Crossing series.
The most valuable of all 60 Treasures.
The necklace seen on the item screen holds an Ankh. Known as "Amulet" in Japanese.
A "DK Barrel", from the Donkey Kong Country games. Originally a normal barrel from the same series.
The scale of a mythical creature, Lamia.
Known as Taketori no Musume (The Bamboo Cutter's Daughter) in the Japanese version, this treasure is a clear reference to The Tale of the Bamboo Cutter, a folk tale well-known by Japanese children. In the story, the baby Princess Kaguya is discovered inside a glowing bamboo stalk.
"Kart Tire" in Japanese. A probable reference to the game Super Mario Kart.
One of three Sacred Treasures in Kid Icarus.
Looks similar to many depictions of a tanuki, a mythical shape-shifting raccoon from Japanese folklore. It also resembles Pon, though this character would not appear until Kirby's Dream Land 3.
Orihalcon is the most powerful forageable material from Golden Sun: The Lost Age and Golden Sun: Dark Dawn.
Orichalcum is a mythical stone of Atlantis that is incredibly hard, and quite valuable in most RPGs.
The Great Cave Offensive appears as a stage in Super Smash Bros. for Wii U and Super Smash Bros. Ultimate. All four sections of the cave form a stage. The Sub-Tree Area is at the top, the Crystal Area is to the right, the Old Tower is in the bottom middle, and the Garden Area is in the bottom left. This stage features Treasure Chests, mine carts, cannons, and Danger Zones, which can instantly KO players with more than 100% damage. Treasure Chests can be broken and will drop items. Players can ride and dismount from mine carts, using them to attack other players. The cannons act as they do in Kirby Super Star/Kirby Super Star Ultra: they continuously rotate in eight directions, and players who enter can be shot out by pressing a button. However, not every angle is preferable, as firing straight down will result in a self-destruct.
The Great Cave Offensive and its Ω and battlefield forms can be played in 8-Player Smash.
While on a picnic, Kirby fell into a huge cave. Rumor has it that this cave is full of treasures! Can Kirby find all of the treasures and make it out of the dangerous cave alive? We shall see.”
The burning red Danger Zones are as dangerous as their name implies. Touch them with more than 100% damage, and you'll be instantly KO'd.”
— Danger Zones • Super Smash Bros. for Wii U/Super Smash Bros. Ultimate
On this stage, mine carts will sometimes appear. They start moving when someone gets inside or on their own after a while. Try not to get run over!”
— Mine Carts • Super Smash Bros. for Wii U
The Old Tower is fully optional. The player does not need to fight Chameleo Arm, even if he/she chooses to enter the Old Tower. As such, the location is skipped entirely in Meta Knightmare Ultra with the gates being shut.
Commas were added to the gold values in Kirby Super Star Ultra.
In Kirby Super Star Ultra, the new treasures have different values, but the total value of all the treasures is still 9999990G.
If the player completes the game without collecting a single treasure, during the ending sequence, "You didn't find even one treasure..." will appear instead.
According to the original Japanese manual, the name of the great cave is "Majirute" (マジルテ).
Before Nintendo formally announced the inclusion of The Great Cave Offensive stage in Super Smash Bros. for Wii U, the company's Facebook page leaked an image and teaser description of it. On October 5, 2014, Nintendo posted a weekly wrap-up highlighting the biggest updates announced in the last seven days—among these was an image of Kirby and Pikachu riding in a Mine Cart. This image was never revealed prior to the post.