If you're playing on PC:
Close the game, open it again while holding shift or alt to bring up the Resolution selection menu. Select the resolution that best fits your screen to fix the issue.
If that does not work, you can force a resolution change on Steam by entering -screen-width 1920 -screen-height 1080 in the launch options section.
If you're playing on WiiU:
Look at your TV, the game cannot be played with just the gamepad, unfortunately.