I need help pls

i read this story a while ago about a 30ish year old male who is a shut-in who gets sent this video game about building a village and helping the "characters" survive. however as time goes on he starts to realize that those "characters" actually exist. he gets sent a dragon/lizard by the villagers and also he learns that one of his coworkers is actually playing the same game but instead of being someone that helps the villagers his goal is to kill them by sending monsters. Thank-you