Temple of Yog makes interesting use of the Wii U GamePad’s second screen by having it display a shadow world linked to the light world that you can see on the television.
In order to progress through its deadly Temple, you’ll need to switch your eyes from the TV to the GamePad as you warp your character between the two worlds. You can see how this works in the video above – when coming to a dead end in one world, a passage opens up in the other.
As to what Temple of Yog is about, well, it’s a roguelike with procedurally generated dungeons. You guide Tributes of a class you choose through the titular temple in order to progress. The catch is that everyone who enters the temple dies. However, your aim is to have each Tribute die at the temple’s zenith.
Reaching the top and dying is considered a sacrifice and goes toward progressing the village they came from, advancing it from a “primitive backwater town to a futuristic acropolis.” So you need to have them survive the temple’s carnivorous creatures, including boss fights, while aiming for that sacrifice. And, as the village progresses, you’ll unlock new classes with new abilities brought to them by the advances in technology.
Temple of Yog will be coming exclusively to Wii U once it’s finished. You can find out more about it on its website.