Serving as a remake of Metal Gear Solid (1998), the gameplay of Metal Gear Solid: The Twin Snakes was altered to resemble that of Metal Gear Solid 2: Sons of Liberty (2001). While all of the original areas and enemies were kept, new ways for the player to combat them were introduced, such as the ability to shoot from a first-person view. Enemy AI was improved, giving enemy soldiers the ability to communicate with each other and detect the player more intelligently with senses of sight and sound enhanced.