The game is reminiscent of point-and-click adventure games mostly made for the PC, and uses the unique control mechanics of the Wii Remote. It was directed by Eichiro Sasaki.
- Captain Rose
- Captain Hulk - When Zack talks to him, he will show him the main world map, whereby players can select a mission to try to tackle.
- Johnny Style - The bunny pilot of Zack and Wiki's airplane, which crashes into an island at the beginning of the game. He is also the game's mechanic and rough around the edges, but well respected by the others. His favorite expression is "Oh my!"
- Loafrey - Loafrey tells players how to operate items and contraptions in each of the missions of the game.
- Dimmy - When Zack talks to him, he will give hints about how to progress through the game, as well as rumors. Hearing new ones will add them to the Rumors book on the bookshelf.
- Maddy - The adventurous Maddy shows up a little ways into the game, offering to search the world for treasure. Point to any spot on the map and he'll take off for it, coming back after the next mission is complete. It costs coins to send him out, more for sending him further away. Once he comes back, he'll show the treasure he's found, which varies in number and rarity.
- Goons - Rose's army of frog bomb-toting henchmen, who obey her every whim. She is verbally abusive to them, and does not seem concerned in the slightest if they are endangered as long as they heed her.
- Growlin' Goblins - A strange group of savages living in Jungle Ruins who seem to be under the influence of a magic flute.
- Hint Oracle - An odd character calling herself "Granny" who sells Zack either Oracle Dolls which provide players with a clue as to what to do next, or Platinum Tickets which allow players to continue from where they left off if they lose a life. She tries to pass herself off as two separate people by donning a blonde wig and fake angel wings.
- Jeeves - the master of the Ice Temple stage created this broom-carrying robot to help with garden maintenance. Unfortunately, it won't let the master step foot outside now.
- Bonelich von Skeleski - is the conductor of Barbaros's famed orchestra. He is a powdered wig wearing skeleton and haunts various locations in the game. Ringing Wiki near him will wake him up and a minigame will begin where the player must play a classic Capcom song by shaking the Wii Remote. If the player succeeds in the task, Bonelich will gives out treasures or upgrades for Wiki.
- King Growl - (Jungle Ruins Boss) - The real king of the jungle and a powerful beast. The ruins may tremble with his every footstep, but he's one banana short of a bunch.
- Swellosaurus - the "Ancient Wyrm" found in the Volcano Cavern stage, this massive beast is the parent of a baby dragon which accompanies Zack.
Zack aspires to be the greatest pirate ever. He and his "enchanted" friend Wiki are the newest members of the pirate gang, "The Sea Rabbits". On their flight to the Sea Rabbits' hideout, Zack and Wiki crash land on an island. On the island, however, they find a treasure chest with the golden talking skull of the legendary pirate captain Barbaros who promises to lead them to his famous Treasure Island and give them his Legendary Ship if they will restore his body, by collecting the various pieces of his body scattered around the area.
Zack and Wiki search through several areas of the world, each one containing either a missing piece of Barbaros' cursed self, or a map leading to other areas. While they explore these areas, they frequently run afoul of the Rose Rock Pirates, a group led by the bourgeois Captain Rose and crewed by her band of seemingly indestructible Goons.
Finding the last piece of Barbaros in a chest in his own castle, Zack rings Wiki in order to restore Barbaros to his former self. This restores Barbaros' humanity, but also reveals his true intentions; that he never planned to give Zack anything, and wishes Treasure Island all for himself. It is also revealed that Wiki was the one who originally cursed Barbaros, which Wiki had lost memory of. Barbaros then casts Zack and Wiki into a pit and departs for Treasure Island.
Zack and Wiki give chase and join forces with Captain Rose to trail Barbaros to Treasure Island, an island that seemingly floats in the gap at the center of the earth. There, the heroes outsmart Barbaros and escape Treasure Island with his Legendary Ship. As they escape, Barbaros attempts one final assault using a large mechanized creature. Zack is able to repel this assault in the end, but at the cost of losing Wiki to the collapsing Treasure Island. The epilogue details life soon afterwards, with a despondent Zack in the Sea Rabbits' hideout. He hears a familiar ring and rushes out to find a chest washed onto the shore. The game ends as Zack opens the chest.
Zack & Wiki is presented as a third-person perspective adventure game, with the player controlling the actions of Zack through the Wii Remote. The player can point to objects on the screen, identified by a cursor, to have Zack investigate the item or move about the level. Enemies in the level can be transformed into usable items by having Zack shake his companion Wiki like a bell. When the player has Zack interact with a usable item, the game shifts to a first-person view, and the player must mimic the operation of the item with the Wii Remote. For example, to cut down a tree with a saw, the player holds the Wii Remote horizontally and moves it back and forth. Successful actions are awarded points based on the cleverness of the action, how many attempts it takes to perform the action correctly, and the difficulty level.
Wiki's magical ability involves him transforming living creatures into inanimate objects or tools which Zack can use to further his quest. Descriptions come straight from the game.
- Centipede - No matter the heat or cold, this giant centipede is ready to make its appearance. It's even a known delicacy in far off lands. Becomes a Centi-Saw.
- Snake - A common reptile found to make its home in a wide variety of environments. Fear not though, this tenacious slitherer is not poisonous. Becomes a Slither Gripper.
- Spider - A giant spider with a creepy pattern on its body. Rather than use webs, it skips the middleman and leaps straight for its prey. Becomes a Spidaracket.
- Frog - Bigger than the palm of a hand, this stout amphibian will eat everything. Lately, they have become more and more popular as pets. Becomes a Frog Bomb.
- Bat - A big fellow that likes dark places and hanging around. It has learned to eat its food in one swallow to avoid dropping crumbs on the clean floor. Becomes a Batbrella.
- Boar - This charging bovine will try to ram any moving object. It looks upset while running, but that's just an image it's trying to maintain. Becomes a Boarammer.
- Mole - Unlike typical garden-variety moles, this breed dislikes narrow spaces. It even sleeps outside of the hole it digs because it's too cramped. Becomes a Moldrill.
Mysterious Treasures Edit
Hidden in every mission is a special treasure. These treasures take the form of icons from some of Capcom's oldest and most classic games. They're hidden well and most often require Wiki's bell to appear. Players don't get anything special for getting all of them, they just go towards the treasure total. For completists and hardcore Capcom fans, these are the most challenging and rewarding parts of the game. These include the following:
- Exed Exes
- Ghosts 'n Goblins
- Section Z
- The Speed Rumbler
- Side Arms
- Bionic Commando
- Mega Man
- Armored Warriors
- Captain Commando
- Mega Man X
- Eco Fighters
- Zack and Captain Rose's likenesses appear in We Love Golf! as cosplay outfits for Leo and Marissa respectively.