Perhaps the old marines are angry because the new marines have stolen their jobs and have decided on taking revenge against Adrian and chums. You start in a small hut with a squad of 4 of the friendly Opposing Force marines, surrounded by an outdoor area filled with the standard Half-Life marines who want to kill you. Strangely, although it is an Opposing Force, it’s still a grunt-fest (rather than a Black Ops fest). This better not be the trend for Opposing Force levels, because this is awful.