What games can be played with GameCube controllers on the Wii U (other than Smash Bros) using this device?

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What a chuckle

Actually yes you can play Mario kart 8 with a game cube controller And Pokken Tournament

But its a special adapter by the same people

Here you go OP

mayflash.com/Products/NINTENDOWiiU/W007.html

^This right here lets you play all the Wii U games with a Gamecube controller as long you have a Wii mote plugged in you'll be fine

how's the input latency on those things? Also when are they going to launch one compatible with all consoles from shit like the magnavox up to maybe current/last gen just for feature's sake?

Smooth

Shucks, I already bought the other one. Also, they seem to have ceased production, but I bet I can get it on eBay.
So basically it makes the GC controller into a Classic Controller or a Pro Controller sorta?

pretty much it just treats it as a pseudo -Classic controller

It has turbo functions so just be careful
Turbo mode just makes it annoying to hold down the accerlation button for MK8

You can use it on PC to play Rivals of Furryther.

And why, pray tell, would I want to play that?