This paper reviews the literature on the use of digital simulation games in computer-assisted language learning (CALL). The discussion explores research approaches, contexts, methodologies, findings, trends and issues in peer-reviewed research that has investigated the use of this type of digital game over the period 2005 to 2020. Results showed that in a majority of studies, a simulation game was implemented in an experimental project. In terms of research context, most studies were carried out in universities in North America and EFL students were the most common participants. Most studies involved the collection and analysis of both quantitative and qualitative data. The majority of studies investigated vocabulary learning and data indicates that playing this type of game may enhance L2 vocabulary knowledge and retention. In addition, positive findings relating to affective factors are reported across the majority of projects. Analysis reveals that research is focused primarily on the above areas and that other aspects of learning remain under researched. It was also found that studies are subject to significant limitations. As findings from the current body of research are not conclusive, more work appears needed in order to clarify if simulation games represent an effective means to enhance learning outcomes. The discussion concludes by identifying areas of interest for investigation in future research and practice.