Chaos Emeralds
Sonic the Hedgehog
Announced in 1997, this game took up until 2011 to release, to terrible reviews all around.
Duke Nukem Forever
An accessory for the Nintendo Gameboy that allowed one to take pictures, edit the pictures, and create original drawings.
Gameboy Camera
A Social Deduction Game that transports you back to 1933
Secret Hitler
In Pokemon Red and Blue, looking under a truck in Vermillion City would allegedly find you this Pokemon.
Mew
"Would you kindly?"
BioShock
Jiggies
Banjo-Kazooie
Valve infamously announced the game was being delayed on this game's release date.
Half-Life 2
This accessory was on the Xbox and the Xbox One and was a motion controller for both consoles.
Kinect
After sabotaging your friends, you utter this game's name.
Sorry
"L is real 2401" was a message in Super Mario 64 that allegedly meant you could unlock this character by collecting every coin.
Luigi
"Do you think love can bloom, even on the battlefield?"
Metal Gear Solid
Riddler Trophies
Batman: Arkham City
DAILY DOUBLE
This Kirby game was planned for the Nintendo 64 in 1995 and scrapped, before being released on the GameCube in 2005.
Kirby Air Ride
This add-on had an LED scanner that read paper cards with encoded data on them, which were used to unlock secret items and levels in video games on the Nintendo Gameboy Advance.
Nintendo e-Reader
Thought up in 1903, this game is an intense critique of capitalism.
In Super Smash Bros. Melee, if you defeated 20 enemies in Cruel Melee, you'd supposedly unlock these characters.
Sonic and Tails
"I used to be an adventurer like you, but then I took an arrow to the knee."
The Elder Scrolls V: Skyrim
Eight Melodies
MOTHER
This Metroid game was leaked in 2005 and scrapped twice before being released sixteen years later.
Metroid: Dread
This add-on increases the memory of the Nintendo 64, allowing people to play games such as Donkey Kong 64, Legend of Zelda Majora's Mask, and Perfect Dark.
N64 Expansion Pak
DAILY DOUBLE
This board game is responsible for inspiring a 2012 box office bomb.
Battleship
Clear arcade mode, go ten rounds with the final boss without either of you landing a hit, and then you'd unlock Sheng Long in this game.
Street Fighter II
"Stay a while and listen"
Diablo
Pure Hearts
Super Paper Mario
This game by Square Enix was announced at E3 2013 but would not be released for six more years after constant delays.
Kingdom Hearts III
A microphone accessory for the Nintendo Wii, allowing voice chat.
WiiSpeak
A humorous take on roleplaying games, focused on killing monsters and stealing treasure.
Munchkin
There was allegedly a forbidden track in this racing game, caused by the last world having one less level than the rest.
Diddy Kong Racing
"What is a man? A miserable little pile of secrets!"
Castlevania: Symphony of the Night