Saving your progress in Metal Gear 2 is vital, as the game can be quite challenging. You can save your game by using the Transceiver (Codec). Access the Transceiver from your inventory and contact your support team. They will provide you with the option to save your current game state. It's highly recommended to save frequently, especially after completing a difficult section, acquiring a crucial item, or before entering an area you anticipate will be challenging. There are no auto-save features, so manual saving is your only way to preserve your progress. Losing significant progress due to not saving can be incredibly frustrating, so make it a habit to call in and save whenever you feel it's appropriate.
