A lot of games have been announced for the Wii U, but there are still many rumored games that have not been announced. Here's list of games that may, or may not, come out for the Wii U, including those made up entirely of rumors and those that have been announced but which I’m skeptical about due to a lack of hard information or very distant release date.
For a list of verified Wii U games, go here.
Shadow of the Eternals
What it is: a spiritual successor to Eternal Darkness: Sanity’s Reqiuem
Definite? No, it's just being put up for crowd funding.
Source: Nintendo World Report.
What it is: A new entry in the futuristic racing series.
Source: Tweet from someone at Shin'en, a developer that has made eShop titles for the Wii U and Wii.
What it is: A puzzle-adventure game that looks a bit like Myst.
Source: After announcing PS4 exclusivity, they posted on their that this was temporary exclusivity and that it would be "a while" before it comes to the Wii U or next Microsoft console. The developer later said a Wii U version was "unlikely."
Rainbow 6: Patriots
What it is: FPS
Source: Rumor from Nintendo Enthusiast from an article where they correctly predicted a Wii U "Watch Dogs" announcement.
Anima: Gate of Memories
What it is: Kickstarter-funded sequel to the Wiiware title Anima: Ark of Sinners
Source: WiiUDaily says it will come out for the PC/Mac then later for the Wii U, although I haven't found any platform information on their website.
Mass Effect Trilogy, Mass Effect 4, or both
What it is: Action/RPG series entries
Source: A Bioware rep, in the context of the Wii U, said the company has "plans for the Wii U.
Lost Planet 3
What it is: Entry in the Snow-based action game series.
Source: Game Informer.
What it is: An action/RPG that has only been announced for iOS.
Source: Source code of a teaser website.
Grand Theft Auto V
What it is: Upcoming entry in the open-world action crime game.
Source: Listing by a Swedish game retailer. It probably isn't actually in production now, but Rockstar's Vice President says it's a possibility.
Kid Icarus Uprising
What it is: Presumably a port of the DS game.
Source: A listing on a French site, with mocked up box art for the Wii rather than the Wii U.
Star Fox - Metroid: Fusion Saga
What it is: A rumored combined-franchise title possibly being developed by Retro Studios.
Source: A game journalist.
What it is: Entry in the FPS series.
Definite? No. Rumors come and go on this one, but nothing has been decided, let alone started, and no decision is likely to even be made before the PS3/360 versions are released in early 2013.
Source: Click Online.
What it is: A untitled game being developed by Vicarious Visions.
What we know: Nothing except the code name.
What it is: Gaming god Jordan Mechner's remake of his first game.
Definite? Maybe; there's an ESRB rating for it.
Rumor source: ESRB via Joystiq.
Definite? Probably, but the developer said he couldn't be specific but would "expect to see it on" the Wii U.
Source: Interview with developer.
What it is: Part of the Colin McRae Rally racing series. No word on whether this is a port of one of the existing games or something new.
Definite? Who knows? This was announced as being a Wii U title in 2011, but nothing's been said on the subject lately.
What it is: Something in the Formula 1 series.
Release date: Unknown.
Tom Clancy’s Ghost Recon Online
What it is: A third person action MMO. It will be released this year on the PC as a free-to-play, downloadable game, and Ubisoft says they would like to do the same thing on the Wii U, although they will first have to see if in-game purchases will work on the console.
Definite? Not at all. Ubisoft has apparently put their Wii U version "on hold," and have suggested a decision about whether to produce a Wii U version is a ways off.
What it is: An upcoming third person shooter from the guy who created the Ninja Gaiden and Dead or Alive series.
Definite? Maybe. The company head said in 2011 that he was “very excited” about getting the game onto the Wii U, but there's been no news since.
Battlefield Wii U (Not Battlefield 3)
What it is: Something in the series.
How it would use the Wii U Controller: EA’s president has said the controller might be used for “playing the game from a commander mode” or “being able to drive from a different position inside of a vehicle,” whatever that means.
What we know: There’s a rumor floating around that "some guy" connected with Activision says there will be a Wii U Guitar Hero game. This would be a little surprising, since Activision cancelled development of the last planned GH game, but that’s the rumor.
Castlevania: Lords of Shadows 2
What it is: A rumored multi-platform entry in the series. A rumor was floating around that it might make the Wii U, but word now is it won't, although the producer has said he wouldn't rule it out completely.
Metal Gear Solid
What we know: Kojima Productions, who develop the MGS games, “definitely have things in mind [for the Wii U],” although they sound like they want to wait and see if the console is successful before jumping in. So whatever they may do, don’t expect anything anytime soon.
Medal of Honor Warfighter
What it is: Latest entry in the long-running stealth-action series.
Source: Austrian newspaper said so, but that was long ago and there's been nothing since.
Kingdom Hearts: HD Remix or Kingdom Hearts: Remembrance
What it is: A collection of previous games in the series.
Source: Anonymous Source
Final Fantasy game
What we know: A Square producer says the publisher is “now considering the possibilities of bringing the Final Fantasy series to the format.” The hope is they are considering bringing something in the numbered series to the Wii U rather than the spin-offs they published on the Wii.
Painkiller: Hell & Damnation
What it is: Remake of the FPS.
Definite? No, it's just a rumor based on a mysterious document.
Source: Some Polish business document.