- : Use the joystick, the direction pad on a controller, or the arrow keys on your keyboard to direct Snake throughout your mission. He can move in any of the four cardinal directions, although you cannot instruct him to move diagonally. Use these inputs to direct the cursor on menu screens as well. or
- : Press the left action button, or the N key on the MSX keyboard, to make Snake punch. It can also be used to advance the dialog. or
- : Press the right action button, or the space bar on the MSX keyboard, to instruct Snake to fire the currently active weapon. Also press this button to utilize an item in your inventory such as rations. or
: Press the F1 key to pause and unpause the game.
- / : While the game is paused press the F5 key to initiate saving the game. To properly save the game, you must have a cassette player connected to the MSX. To load the game back, press the F4 key while the game is paused.
- : Press the F2 key to enter and exit the weapon select screen.
- : Press the F3 key to enter and exit the inventory screen.
- : Press the F4 key to enter and exit the transceiver screen. While on this screen, press left or right to change the communication frequency, and press up to attempt communication on the current frequency.
At the start of this game, Solid Snake is a rookie recruit of the elite special-forces unit FOXHOUND. Snake is sent by team leader Big Boss into the rogue nation Outer Heaven to rescue his missing teammate Gray Fox and discover who or what "Metal Gear" is. You control Snake throughout the game.
Snake can move in any one of four directions and he can throw punches. He can use one of seven different weapons throughout the game, provided he locates them and has enough ammunition to use them if they are firearms. Firearms are shot in the direction that he is currently facing.
Snake has a life meter which is shown at the bottom of the screen. The life meter decreases whenever he takes damage by touching an enemy, or getting hit by an enemy's bullets. At any point in the game, Snake can use a ration to restore lost energy if he has any in his inventory.
If the life meter becomes empty, Snake will die and the game will be over. At this point, the player may choose to continue. The game will continue from the last scene change (e.g. entering an elevator, exiting a building to the outside). Any progress made since the last time Snake reached that point is lost.
Snake's class rank is displayed below his life meter. Snake's class will rise when he successfully rescues five prisoners, up to a maximum of four stars. When Snake's class increases, he is able to hold more weapons, ammunition, and rations. See the chart below for more information. Snake will lose a class rank if any captive comes to harm.
In addition to his life meter and class, the current weapon and item that Snake is utilizing is shown in the lower portion of the screen. To change Snake's weapon, press the F2 key. To change the item that Snake is currently using, press the F3 key. Snake can only use one item and weapon at a time.
Class capacity chart
|Rank||Handgun||Sub Machine Gun||Grenade Launcher||Rocket Launcher||RC Missiles||Plastic Explosive||Mines||Rations|