With the rise of free-to-play (F2P) games, the profitability of video-gaming apps critically depends on the ability of developers to acquire, retain, and monetize large numbers of players. In this context, most game designers have no viable alternative than massively collecting players' personal data and monitoring their behavior to target them with personalized advertising and in-game purchases. Given the risks associated with such data practices, players, in particular children, need to be aware that a video game might compromise their privacy. Game designers should therefore ensure that players receive appropriate information about the data practices associated with their games. This might, however, be challenging, especially when the game is directed at children, given the complexity of privacy information and the limited literacy capacities of children and their parents. To answer game designers' need for comprehensive guidance regarding the communication of privacy information to children, we provide a survey of the age-appropriate information design strategies which been recommended by data protection authorities, children protection organizations and the relevant scientific literature. On this occasion, we also refer to illustrative examples of designs which can be considered good practices. Finally, by using an "evaluation matrix", we reviewed and assessed the implementation of those design strategies in nine F2P mobile games committed to following Google Play's Families Policies. Our findings show that, despite being child-oriented, the reviewed games largely fail at communicating privacy information in an age-appropriate way.