The game begins with the protagonist, Solid Snake, emerging from the sea onto a small port with a single path forward flanked by two heavy tanks. His radio transceiver rings and the screen transitions to show Snake receiving his orders from Big Boss: infiltrate Outer Heaven, contact Grey Fox, and destroy the ultimate weapon Metal Gear. The rest of the story is delivered piecemeal from snippets of information gained from rescuing POWs and the occasional radio transmission. Much of the story is unremarkable in this regard. We are told that a kidnapped professor has been coerced into completing Metal Gear at the threat of his daughters life; we are told that Metal Gear is a nuclear capable all-purpose bipedal tank; we are told just about in short bites from NPCs that we generally never see again. It does little to build tension or connect the player to the game's world.

There is, however, one exception. As the player begins to key-in on Metal Gear's location, Big Boss, who has guided the player through the early game--when it is at its most difficult, begins to misdirect Snake. Following his advice results in running into pits, ambushes, and worse. It is only after finding and destroying Metal Gear does he reveal himself to Snake as the founder of Outer Heaven, having intended to feed false information back to the government through Snake. The betrayal is well executed, differentiating itself by being revealed through moment-to-moment gameplay. The ending sequence is similarly cathartic as the player sees Snake, having bested Big Boss and disabled Metal Gear, running into the night as Outer Heaven bursts into flames behind him.

Unfortunately, Snake's allies offer little to write about. The resistance members, aforementioned researcher and engineer of Metal Gear, and captured agent Grey Fox all make brief appearances throughout the story with one of the resistance members acting a shallow love interest. The elite soldiers Snake must overcome each have a unique quirk like tossing boomerangs while surrounding himself with hostages, or wielding a sweeping flamethrower. What they lack in backstory is certainly make up for in visual flair.

Metal Gear is a very simple game. Snake can move in the cardinal directions, punch, and use his current weapon. The four function keys pause, access the item menu, weapon menu, and radio menu. Notably, despite having an item menu, Snake cannot actually actively use any of the many items he finds except for the Life restoring rations. All other items are passive and serve to reveal traps or allow Snake to travel deeper into the enemy base. The only exception to this is the cardboard box which replaces Snake's sprite with a simple box allowing him to avoid detection from enemies and cameras so long as he isn't moving. Conversely, one of the first items players are likely to encounter in the game are a pair of binoculars for which I could find no use. Their strange inclusion and the fact that two keys are bound to the same punching action may suggest that there were grander designs for Snake's abilities that were never realized.

While Metal Gear does feature only a few weapons, they are distinct in their purpose and satisfying to use. The handgun and sub machine gun serve as Snake's all-purpose weapons with the latter being capable of full-auto fire. Both can also equip a suppressor to allow for use without breaking stealth. The grenade launcher offers a unique arcing fire that targets a set distance ahead of Snake. The most unique of the bunch is the remote-controlled missile which, as the name suggests, allows Snake to pilot the missile to its target, often allowing for interesting boss strategies or puzzle solving. Snake also has access to two types of mines, one triggered manually and another by proximity. While the former can be useful for breaking down destructible walls, the latter sees little use due to the fact that any placed mines will disappear when the weapon is swapped.

For much of the game Snake is weak. He can be killed in only a few bullets, has limited access to healing, few weapons, and is typically outnumbered. These unfavorable conditions succeed in their goal of pushing the player into engaging with the stealth elements but they do not come without a cost. Metal Gear often felt like a game of trial and error. I could enter a screen from a poor position, misjudge a guard's movement, or find out the door I had been planning to enter was locked only to trigger an alert, get swarmed, and either die or suffer heavy damage. Unfortunately, the game only saves upon entering one of the few elevators placed around the base, and with healing in short supply, it often meant that it was better to respawn after taking heavy damage rather than risk getting stuck on a save with only 1-2 hits worth of Life remaining. While stealth is intuititive--simply stay out of the enemies' sight-line--the alert phases were not. I never could determine what resulted in the more severe double "!!" alert which called in reinforcements as opposed to the simpler alerts that could be lifted by defeating all enemies currently on the screen. For much of the game, these more severe alerts were synonymous with death due to the sudden appearance of reinforcements from off-screen and overwhelming numbers. In the latter half of the game, Snake also begins to encounter pitfall and other traps that can felt far more akin to a "gotcha!" moment than they did clever puzzles to intuit and work around. Unsurprisingly, I found myself repeating the same sequences again and again throughout my time with the game.

As mentioned above, the player begins their journey with almost no context. Items and weapons are likewise never explained, though most are obvious in use. Big Boss does occasionally chime in to deliver a tip at times, but rarely is Snake actually able to contact his allies on his own terms. There were two mechanics in particular that I was not expecting. The first relates to the many key cards Snake will find throughout the game. These are numbered sequentially and upon acquiring my second card, I assumed that "key card (2)" would also open any of the locks that "key card (1)" could. I was wrong. Not only was the constant swapping of cards tedious, it resulted in me wasting a good portion of my time backtracking to try my earlier keys in areas where I had neglected to test them due to my misunderstanding. The second relates to the game's destructible walls. While Snake can find these by punching them to listen for a hollow sound, this hint isn't given for quite some time resulting in the player spending a significant portion of their time backtracking and checking Outer Heaven for hidden paths.

Combat, however, is generally easy. While the swarms of soldiers summoned by an alert can quickly overwhelm Snake, much of the time Snake is be dealing with 1-2 guards on patrol, They can be easily dispatched through a series of punches or with either of the silenced guns. The bosses similarly pose little threat. Most have clear patterns and safe spots were Snake can strike with either the grenade launcher or guided rockets without fear of reprisal. That being said, with the game's saving mechanic in mind, I certainly didn't have any problem with the less challenging bosses.

Despite billing itself as an action-adventure game, Metal Gear certainly has the feel of a point-and-click adventure game at times. The player often finds themselves traversing the same areas hoping to find a use for their newest acquisition. The structure of Outer Heaven shines in this regard. Often I would pass through a new section of the base, acquire a new item, and then pop-out of a door I had seen much, much earlier, and each step I took towards unraveling the mystery of its mazelike corridors felt more satisfying than the last. Given the setting, Metal Gear's color pallet is understandably drab, but nonetheless we do see a variety of metallic and wooden hues; at one point the player seemingly traverses a desert too! In addition to the common soldier, players will also encounter guard dogs, jetpack wearing goons, scorpions, tanks, the enigmatic bosses, and of course--Metal Gear. There was a strong desire to discover more of the world and uncover the whatever what might be waiting for Snake behind the next door.

Rather than use the MSX2's built-in sound chip, Metal Gear cartridges shipped with the Yamaha YM2149 soldered in. A single track plays in most of Outer Heaven and while atmospheric and almost stressful the repetitive drumming beat did begin to strike a nerve as the game dragged on--particularly because this what I was hearing during the most repetitive sections of the game. Upon triggering an alert, a siren plays followed shortly by an upbeat heroic tune, always a nice change of pace. Once the player delves further into the fortress they will encounter the second sneaking theme and my personal favorite. Tense, eerie, and unnerving, it places the player on edge during some of the more difficult sections of the game. Despite being one of the more energetic tracks, the boss theme does little to stand-out and is ultimately forgettable. The Metal Gear theme is composed of shrill mechanic tones and layered beats befitting the game's titular ultimate weapon. Together, the tracks combine to create a tense, nerve-racking atmosphere punctuated with short bursts of high energy--certainly one of the game's strong points and a great achievement on the hardware of the time.