App with Working Start Button

App.js

import React, {useState} from 'react'; // make sure to import useState

// rather than use magic strings like "playing" and "starting" I'm using an object for our gameState options.
const GameState = {
  playing: "playing",
  starting: "starting"
}

const Game = () => {
  return (
    <Text>The Game will be here</Text>
  )
}

export default function App() {
  const [gameState, setGameState] = useState(GameState.starting)
  const startGame = () => setGameState(GameState.playing)
  return (
    <Container>
      {gameState === GameState.starting && <SuccessButton onPress={startGame} >Start</SuccessButton>}
      {gameState === GameState.playing && <Game/>}
    </Container>
  );
}