UFO2000 is turn-based multiplayer tactical squad simulation game. It is heavily inspired by the famous X-COM: UFO Defense game. While the UFO2000 engine was specifically designed to be compatible with the graphics resources and maps from X-COM, you don't need any proprietary data files to play, as a new fan-made set of graphics is included in the UFO2000 distribution, so the game is ready to run out of the box. If you want an exact X-COM look and feel, you can install original X-COM and TFTD data files to extend UFO2000 with additional maps, weapon sets, and units.