Well, its your decision to make. The main advantages FreeCash team highlight are 1. you can play both with real money and tokens mined during the game; 2. PRIZE tokens can be exchanged for real advertisers gifts. According to practice, those gifts can go as far as to be a car or a golden accessory.
You can't play with real money, you can however you generate in game credits (earned by mining) .
These credits can be exchanged for prizes, in app purchases or cashed out. Depending on user knowledge, this will either be through their hosted wallet (zero knowledge) where we complete the exchange for them, or via their own ERC20 wallet (more advanced knowledge) where they sell on a public exchange themselves. PRIZE is also the way that advertising contracts are bought.