Its too early to be asking for funding. Follow the advice above, find coders that believe in your concept, partner up with them, give them equity, build a prototype/demo/MVP ... prove the concept works and make sure there's a demand for the app - THEN go pitch and ask for investors to add FUEL to the rocket already in motion on its way to the moon.
But don't approach them when you just have blueprints and ask them to build the rocket ship for ya.
If you can't convince coders to join you ... that's the hint it might not be the best idea. They are in the trenches and know what works and what doesn't. Heed their feedback.
At this point they could also just go for a kickstarter campaign. That would show them if there is a large enough customer group, they would get the money to develop the game, and have sold copies as pre-orders.
Rewards and stretch goals for games are also pretty simple and cheap to implement. Just think about stuff like "We will name a character after you", "Be in the credits", "Design a monster" or whatever. Those things ranch from 10min to maybe a day of work at max.
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