HMS Diptera - Version 1.93 Sci-fi first person shooter. Whilst beginning your normal patrol route on the HMS Diptera a radiation wave hits the ship and strange things start to get uncovered... You play as John Reid, just another security guard placed on the night shift. FPS stands for First Person Shooter. FPS games provide complete immersion in the gameplay. In these games, the player completely merges with his character, which gives an incredible feeling. Download free FPS games and enjoy the game without restrictions! Download and play full version FPS games for free!