In this paper we discuss strategies for evaluating mobile games with three to five year old children with regard to usability and fun aspects. The use of smartphones and tablets have made a lot of interactions of children at this age with technology much more intuitive and made a lot of concerns of previous research of less importance. That said, these devices also pose new usability considerations which have to be addressed. In addition, not all proposed evaluation methods are suitable for evaluating games. As even with careful heuristic evaluations some product-specific problems remain undiscovered until children start using the product, it is better to involve children in evaluations as early as possible. Therefore, we present guidelines compiled from literature and describe our experience during the evaluation phase of our mobile game "Hamza" for teaching preschoolers the Arabic Alphabet.