i think most peoples argument about the how short the demo/prologue was, is directly proportionate to the amount of world and character building it provides. none.
basically, most of us cant express interest or disinterest based off the demo cause it was too lacking to take anything from. well aside from killing off the gf so lazily, and the mc just standing there like an idiot.
i mean based on that bit, theres no need for more story, we all know what happens. gf gets eated, mc stands there and watches like a dope, or scared paralyzes, and gets eaten next. the sisters and mom who left him to die were justified in abandoning the one person who they knew would otherwise drag them all down and get em killed.