Tired of your old first-person shooting game which seems to be so repetitive as you go through it day by day? Or perhaps you can't just get over the thought of shooting aliens or maybe you want to fight as an alien this time? Then maybe this is just the game for you. Tremulous is an open-source game for Linux and Windows with a team-based gameplay where players can choose between aliens and humans. It combines FPS with real-time strategy to keep the excitement going on for hours and hours.