Another Bug, when the prompts for enemy digestion show up do not click yes they will digest twice and sometimes even bug the animation and only shows them flat bellied once they move and other times clicking too fast can leave images of characters on your screen
Is your system locale set to English ? that can be the issue with games opening and closing, if not you would need to redownload the game and extract it. other times it could be the file pathing. (I hope you find this to be helpful) if not then idk