For a Nintendo franchise you need more gameplay details.

if you called it "new aqualve bros. wii" or "Call of Magvern: Fantasy warfare ". it would sell better.

Seriously though, you have a decent story arc. you just have to come up with more of what the game would look like. if its 3rd person, 1st person, rpg, action adventure.  Look at games you like and try combining elements from those games.

It would be an Action Adventure. The game can be played in 2 player mode but there is a multiplayer section in the game. During the start of the game you must select either Aqualve or Magvern (Aqualve is female and Magvern is male. Once you die you play as the character you did not select). The rare minerals also give you more power and allow to explore new areas and communicate with intelligent life that you may come across (eg Raiscentians etc). When you defeat an enemy you gain their power. There are alot of puzzle elements in the game and moderate violence.
In multiplayer the are twelve playable characters and sixteen stages. All of the characters start of with ten attacks and during the battle you gain attacks and you can steal attacks.

I would say bad names and bad title but decent sounding gameplay.

Bad names , generic sounding game.

It's fine to be original and make original names, but don't make them a pain in the ass to pronounce or completely forgettable.

Also, out of pure curiousity, why do you say New Nintendo franchise? Do you expect to one day pitch this game to Nintendo? If so, don't waste you time because no game studio will ever take some random persons random idea.

-edit-

And that doesn't mean you should give up on developing your idea into a full fledged design and even possible future game made by you on your own or some completely indie thing, just abandon all hopes of Nintendo or some other developer taking it.

Not only gaming, but the whole existence of mankind will change forevar after this game. Congratulations.

Honestly, it sounds awfully derivative.

So you wield elemental powers and have to collect 45 Stars, gradually becoming more powerful as you progress. Along the way, you interact with NPCs of strange new races. Spread throughout the game are nine boss battles, leading up to an epic climactic fight against the main villain.

With puzzles.

And multiplayer.

My idea of a game about a some people saving the future was better

OT:
It is okay, it needs to be more polished