I wouldn't blame anyone for looking at this footage and confusing it for a Smash Bros. knockoff, or a rejected Nintendo game. Just look at how messed-up the characters look. It's almost like they're crying out in pain, waiting for someone to end their suffering.
But no, it's definitely the Wii U version of Smash Bros. The footage comes from Terrence Boykin, and while it's short, you can take a closer look at this hot mess in these Miiverse posts uploaded by Boykin, too:
The glitches we found in the 3DS version of the game were less nightmare fuel and more just funny. Still, I haven't actually encountered anything like this stuff uploaded by Boykin. Have you?