I've had this idea ever since the official timeline had been released, and I think it would be a pretty interesting concept.
Instead of being introduced to just one Hero, we are introduced to three -- one from each of the timelines -- and are reacquainted with their respective universes. Perhaps one or two of the Heroes are a reincarnation we have already seen (such as from
ST or
AoL ) so that we won't have to have three origin stories -- that would make things painfully slow.
Now, the conflict. Since Ganondorf is seemingly dead as a doornail in all timelines, it is perhaps time to introduce a new villain who is not only aware of these three different universes, but can also travel between them and plans to unite them under his rule (I'm sticking with the generic villain archetype for now just for the sake of the discussion). This could perhaps alert a friendlier being with the same abilities, and motivate said friendly being to visit the three universes and recruit the Heroes from each.
I think it would be interesting to see different artistic/graphical styles we have seen thus far in the series somewhat connect, and this connection can be done in such a way to make the gameplay enjoyable as well. I'll explain:
1.) The Adult Timeline focuses on a more colorful Hyrule with overall a child Link. The main theme of this timeline seems to be the advancement of technology, as we can see in
PH and
ST. Perhaps the gameplay of this segment of the game can revolve mostly around technology and transport, with a younger Link using some sort of engineering skills to help the "Friendly Being" (as we'll call it from now on) and the other Heroes. The items this Link will be given are more technology-centered ones, such as a Hammer (either like the Megaton Hammer or Skull Hammer), Bombs, etc.
2.) The Child Timeline focuses on a more dark and violent storyline, with maturity and somber seriousness being its main "theme" -- it also has one of the only Links who is an adult for an entire game (with the exception of
Skyward Sword). Perhaps this segment's gameplay can revolve mostly around an older, more serious Link whose main focus is combat. As such, this Link is given more combat-oriented items, such as the Bow, Ball and Chain, etc.
3.) The Decline Timeline features the classic Legend of Zelda, along with games that follow its formula (such as the handhelds) of a young hero who explores dungeons to collect some sort of valuable, with puzzles being one of its main themes. As such, this segment will have gameplay that features complex and creative dungeons that this Link will have to go through. As exploration is a big part of this concept, this Link will have items that are needed in dungeons more than they are in combat: the Hookshot, the Boomerang, etc.
This would give us the character types for all three Links: the Craftsman, the Warrior, and the Adventurer.
Now, while all three universes will have their own themes of gameplay, they do not have to be completely 100% dedicated to those themes. For example: while the Adventurer's gameplay will be dungeon-based, the other two Links could perhaps have dungeons of their own that fit with their respective gameplay -- a dungeon full of enemies for the Warrior is something that comes off the top of my head.
It would also be interesting to find something in one universe that that certain Link cannot handle -- in this case, we'll say a boss. Say the Craftsman finds a boss that he is having trouble with, so the "Friendly Being" transports the boss to the Warrior's universe, where the more battle-experienced Link can deal with it.
Now, what's up for debate is how switching between the Links would come into play. I personally think it would be best if switching from one Link to another is
not a control that players can do whenever they want, and instead are scripted so the plot can unfold linearly.
As for the goal: Perhaps at first the main focus of the game is to stop the antagonist from attempting to rule all three timelines by trying to unite them and send him away for good, but halfway through it is realized that the "unification" of all three timelines would be a catastrophic event and cause a sort of "time crash", destroying everything in existence. However, as the villain is a deluded megalomaniac, he refuses to listen to reason and continues his plan to unify the timelines.
Perhaps the final fight with the antagonist could at first consist of three battles: one in the Adventurer-universe, one in the Warrior-universe, and one in the Craftsman-universe. Then, in a last-ditch effort, the antagonist turns himself into a powerful monstrosity surrounded by a labyrinth-like dungeon in some hellish timeline of its own creation. In this final battle, the Links finally come together to destroy the antagonist: the Adventurer breaks into the dungeon and opens it from the inside while the villain attacks him. Once the dungeon is opened, the villain comes out and the Warrior does battle with it, severely weakening it. The villain attempts to flee, and must then be followed by a weaponized locomotive engineered by the Craftsman, who finishes the villain off. The villain is then reduced to a powerless being and is sealed within his own "timeline".
It can then be apparent that -- for now -- all timelines must continue to exist, and that the Heroes of each one must still protect them while the "Friendly Being" continues to search for a way to combine them all once again.
Aaaand, I do believe that's it. I personally think this would make for a very fun Legend of Zelda game.
What do you think?