A virtual pet breeding and raising game for the 64DD that was being developed by Shigesato Itoi, Shigeru Miyamoto and Pokémon producer Tsunekazu Ishihara. In the game, you raised and cared for an unspecified creature. The game used the 64DD's internal clock so the creature and the world it was in would continue to grow and change, even when the game wasn't being played. It was also intended that the creature could be transferred to a Game Boy cartridge so players could continue to care for the creature on the move. Expansion kits for the game were also planned, although it was unclear how these would have been distributed. The game was discussed a number of times during 64DD development, and a playable version of the game was planned to be shown at Nintendo Spaceworld 2000, but it never appeared. In an interview, Shigeru Miyamoto stated that the game had been dropped due to the team being busy with other projects. It is believed that several of the game's ideas were later used in Animal Crossing and Nintendogs.

Simulator / Strategy / Adventure / Action / Fantasy
Eat or be eaten! Assume the role of an animal in it's early stages of evolutionary development. As your animal instincts take over, you will boldly traverse hostile environments, savagely stalking your prey to assert your place in the animal chain of power. Will you have what it takes to become the new king of beasts? The game started development on the Nintendo 64, but went unreleased, being later ported to the Nintendo GameCube. A prototype of the Nintendo 64 version has been found

Traverse various areas and take photographs of different types of Pokémon by discovering their secrets. Capture the perfect frame to gain bonus points from Professor Oak in order to unlock helpful items and locate and photograph the elusive Mew, a legendary Pokémon whose existence has never been recorded.

Simulator / Adventure / Action / Fantasy
A mysterious game that was being developed for the 64DD by a team at HAL Laboratory headed by Yoichi Yamamoto, a former construction engineer. While little is known of the game in its original form, it is believed that many of the game's features were later incorporated into Pokémon Snap, developed by the "Jack & Beans" team.

Simulator / Adventure / Fantasy
Wonder Project J2 takes place 15 years after the events of the first Wonder Project J game and focuses on a gijin (robot) girl named Josette. The game begins with Josette leaving her home on Corlo Island and traveling to Blueland, where she must learn to behave like a human and ultimately stop an empire from destroying the world.

Platform / Simulator / Action / Fantasy
Super Mario's Wacky Worlds is a cancelled Mario platform video game in development by NovaLogic for the Philips CD-i system. The game was designed to be a sequel to Super Mario World. While an early prototype of the game received positive feedback from Nintendo, the game was cancelled due to the declining sales of the Philips CD-i system.

Role-playing (RPG) / Simulator / Adventure / Fantasy
Similar to the previous work "Tears to Tiara: The Land of the Flower Crown", it is an "adventure + simulation RPG" that follows the fantasy world view and repeats the adventure part and the turn-based battle part to advance the story. It is also positioned as a gaiden work, and the battle system has been changed and added according to the original story.

Role-playing (RPG) / Simulator / Strategy / Fantasy / Warfare
Yggdra Union was remade/enhanced for the PSP with redrawn graphics, voice acting, some new characters, new/edited maps and an increase to 8 units brought into battles instead of the original limit of 6. "Yggdra Union tells the story of a princess ousted from her country and her mission to win it back from the Imperial Army. From a bandit king to a valiant knight, to a young Undine girl, Yggdra is joined in her mission by an ever-increasing band of rag-tag adventurers. Each of them has his or her own beliefs and ambitions, but as thier paths cross, they soon find that protecting what they love most means somehow finding a way to stop the Empire. Get ready for one of the most unique and engrossing straegy games ever to hit the PSP!"

Role-playing (RPG) / Simulator / Strategy / Fantasy / Comedy
The Sims 2 for PlayStation Portable delivers a unique third-person experience that blends life simulation with role-playing elements, offering a more substantial storyline compared to other versions. Players navigate various goals to unlock content while customizing their pre-built homes with furniture and decor. Interactions and jobs are executed through mini-games, maintaining a dynamic gameplay flow. In this version, characters do not age, marry, or have children; however, they can pursue significant relationships and WooHoo. Goals largely dictate relationship dynamics, with close friends potentially moving in as the game progresses. As players complete objectives, their sanity meter, symbolized by a Plumbob, increases, while failing to meet goals leads to rapid depletion, resulting in hospitalization or alien abduction. Unique to this version are "Sanity Points," awarded for completing tasks to unlock special perks, and hidden "Secrets" found in Strangetown, enhancing exploration and social interaction.