It's a Mii.

Nintendo's Wii U is the company's new console with HD support, and to prove it we've got 720p screenshots of one of the games on display at this year's E3, a project Nintendo is calling New Super Mario Bros. Mii.

As you can probably guess, the game is similar to New Super Mario Bros. Wii with one important exception: players can use their Mii characters alongside Mario, Luigi and Toad players.

Nintendo's not claiming this is a game at the moment, it's just using it to show off the potential for Wii Remote and Wii U controller players to play alongside each other. It does look nice, though.