The development and evaluation of prototypes is an important part of game development. Using an iPad, this study aimed to establish whether the fidelity of the prototype affects the ability of children to evaluate the user experience of a game. The participants were aged between 11 and 13 and used the Fun Toolkit to measure user experience in both fidelities. The results showed that the majority of children rated the low-fidelity version lower in terms of look, control and idea with the most significant difference being for the construct relating to the overall experience of the game. When evaluating monetary transactions with children it is important to realise that parental controls might influence the results.