Other than fighting, you have the ability to interact freely with characters and the gaming environment. To increase the sense of immersion, there is no interface or 'HUD' on screen at any time during normal gameplay. Instead, more intuitive methods are available for you to assess your condition, ammunition levels, and other relevant information. The combat within the game is extremely realistic, with a detailed damage and healing system that breaks down the healing process into conditions and treatments - rather than having the typical FPS 'health packs' lying around everywhere.