Be aware of Wii U’s ‘Automatic Shut-off’ feature
Those purchasing a Wii U at launch should be wary of the console’s ‘Automatic Shut-off’ feature, which is turned on by default.
Predictably, as with other consoles, it turns the system off “if there has been no input for a set period of time.”
IGN report that this includes when a game is running and paused, but the player hasn’t interacted with the system in any way for the specified time limit.
By default this is set to occur after an hour, so it is recommended that you delve into the system settings to ensure that you either turn off the feature entirely, or adjust the time limit appropriately. Problem solved!