This is a prequel and a spin off to The Legend of Zelda: Majora's Mask. It goes into depth on the origin of the Fierce Deity Mask, and explains more history about the land of Termina.

-Story-
Ages ago when the land of Termina was being created the four giants took it upon themselves to create two entities that would protect the land where they could not. These two god-like life forms were to serve and protect the people that would inhabit the land. The two beings were called Majora and Oni. However these entities were far from perfect. Because of the young land they became arrogant and began to compete for power between each other.

Neither of them were aloud to show themselves to the people of Termina, but the both of them quickly began to break the rules. Majora appeared to them as a thief and trickster, and many people learned to fear his deception. Oni appeared to them as an angry god and demanded offerings from them. He was soon labeled by the people "The Fierce Deity." The four giants grew angry with the both of them and ordered them to halt all contact with their people. Majora and Oni disobeyed the giant’s orders and soon broke out into an all out war against each other causing destruction to the land. The giants quickly took action and imprisoned the two of them in the earth far beneath Termina. But before the giants trapped them they stripped them of their powers lowering them to simple life forms. Both of them still possessed incredible magic abilities but they were no longer god-like entities.

-First Level-
The first level puts you directly into the middle of Oni and Majora's war. It is mainly a battle sequence. You are given amazing magic abilities that you aren't sure how to use yet, but that isn't the point of the level. This level is to just give you an idea of the controls and magic system by letting you fight Majora, while destroying parts of Termina. Once a certain amount has been destroyed or a certain amount of damage has been dealt, the giants will step in and end the first level by sealing you and Majora under Termina. Once the cinema is over you find yourself in the first dungeon. The catacombs under Termina. Majora has chosen to go one way and you set out on your own with no weapons.

-Weapons-
This game depends more on a magic system of spells and enchantments rather than a weapon based system. It does include a standard weapons system as well, it is just not as large as the magic system. Weapons would include the beam sword that Oni Link possessed in Majora's Mask and special gauntlets that allow many different small magic attacks, such as a simple beam/missile and protection because he doesn't carry a shield. The magic attacks range from those as small as an arrow, with the gauntlets, to ones as big as lightning storms with special medallions and orbs. It would also see familiar spells from older Zelda games like the Ether medallion from a link to the past and Din's Fire from Ocarina of Time, to name a few. With new and more interesting spells like the Ghost Parasite Orb which releases several small green strips that home in on an enemy and eat it from the inside out.

The orbs and medallions do not require magic power to use. This game does not include the magic bar system. Your character holds extreme magic power so instead its measured like the carrots on Epona or the blast mask from the previous Majora's Mask. You can use it once but you have to wait a long time before you can use it again, you must let your orb or medallion recharge. You can use it before its fully recharged but the attack does a significantly less amount of damage. So the strategy is to use what spell when, or what ones to use on what creature. Because some creatures may be more tolerant of a certain spell than another.

-Special/New Features-
This game isn't in the direct line of Zelda games, it is a spin off. So you don't ever get to play as link. The whole game revolves around your character Oni(The Fierce Deity). However the game will have many references to what will happen in Majora's Mask, references like Majora cursing that he will one day crash the moon into the land, and of a boy that will one day finally rid the land of evil. And of course in the end you will find out how and why Majora and Oni were trapped as masks forever.
The game will play very much like both N64 Zelda games and will follow their visual style. However new game play elements will be introduced as you progress. Things like as you become stronger and more like your former god-like self you gain abilities like flight, control over weaker creatures, and the ability to manipulate your surroundings.