Played it on Subsistence, but it's still great...
You start the game as Solid Snake, the man who singlehandedly took down the seemingly impenetrable fortress Outer Heaven. He now has to infiltrate a new soverign nation called Zanzibar Land and destroy the new Metal Gear as well as the people associated with the project.
First off, I have to adress the biggest problem you will have if you play this game on Subsistence. At certain points in the game you'll need to refer to the software manual to contact certain characters via the radio. The problem with this is that you don't have the original software manual and as a result, you're left with no clue on what to do next. You'll need to either get the original copy and use the software manual from that, or go the easier way and refer to some of the strategy guides that go along with this game's page. Just make sure you write down all of the information that includes looking into the software manual so you can avoid taking multiple refrences to the guides given.
Moving on, the graphics are a decent improvement from the original Metal Gear. You have a wide variety of environments, both indoor and outdoor. They all have their own special characteristics, such as traps and vents. Although most of the indoor environments repeat themselves as you play, the outdoor environments rarely look the same. You have jungles, deserts, swamps, and more dangerous terrain to sneak through. The characters look a little less stumy and squashed than before, so you can actually recognise most of them. The enemy guards show little diversity, though. You either have guard A or guard B to contend with throughout the entire course of the game, which leaves few elaborate ways to dispatch them and focuses more on a simple 1-shot kill than anything else.
The gameplay is essentially the same as the previous game, but there's 2 huge differences. The first addition is the crouch button. This allows you to sneak under tables, crawl through vents, and take cover under various objects as well as crawling through gaps. The second major addition is the radar. The range of the radar is 3 X 3 and has a square in the middle that indicates your position and also uses white dots to indicate where your enemies are. The radar is used to its full potential in some of the weapons, making it easy to clear out enemies in an area, but the problem with that is it defeats the purpose of hiding in the first place. At least the guards are smart enough to see you, right? Well, the answer is both yes and no. Sure, they can see you if they look directly at you, but their field of vision only spans a single square, which makes it a pain to guess where they're looking before you enter their square. This cause an uncountable number of alert stages and got annoying right from the get go.
The bosses make the game interesting, though. You have a decent number of bosses and they each have their own tactics for dispatching Snake, whether it would be trapping you or simply charging at you. Some of these bosses can be defeated with no problem at all, but some of them are just plain annoying and in the way, making it far too easy to dispatch them.
Overall, this is a great game, even though I played the subsistence version. Go get Subsistence if you want to find out what the series was like before Metal Gear Solid, but for those of you that don't...well...alright.