In resume this anime is psycho and blody..yes!.. Don't get fooled by the children faces...they are all potential killers, victimsd and full of secrets. The anime revolves around a very small town on the early 80's, and the kids always reviving the same summer with smaller twists that always end on tragedy because the influence of an external factor. These game looks related to the second season of the show, no idea how is it works,  but looks like an interactive novel,  maybe if you watched the anime you can "guess" which structures leads to which ending..