The behavior you've described—playing video games for at least six hours each day and getting upset when having to interrupt that activity for family dinner—could suggest issues related to impulse-control disorders. This is because the individual may have difficulty controlling their desire to play video games, which impacts their ability to engage in other activities, like spending time with family.
However, it's important to note that a full assessment by a mental health professional would be needed to determine any underlying issues definitively.