Serious games are recognized as a relevant tool for educational and therapeutic purposes, including those for individuals with Autism Spectrum Disorder (ASD), a neurodevelopmental condition characterized by difficulties in social communication and particularities in sensorial perceptions and stimuli, such as auditory. This difference in auditory processing affects the everyday behavior, social interactions, and daily life of individuals with autism. Hence, to inform the design of serious games that properly address sound aspects to provide a better gaming experience and contribute to the well-being of autistic players, it is essential to understand how auditory stimuli affect their gaming experience. As an initial step toward bridging this gap, the present study examines 49 papers in a Literature Review, aiming to identify how audio aspects have been considered in the design and evaluation of digital games for individuals with Autism Spectrum Disorder (ASD). Results show that, despite the diversity of purposes that sounds can assume in digital games, only few studies considered audio in the evaluation (whether from the user or from the game) and just as few games mentioned auditory feedback in their design. The results analysis corroborate that the effect of audio in games for autistic users still needs more attention. Furthermore, our findings bring discussions about the great predominance of autistic children as target users of game designs and evaluations, about the lack of evaluation of entertainment games with this audience, with a considerable prevalence of serious games and also about the heterogeneity of validations of therapeutic and educational games developed for autistic people.