I haven't found a really full, let alone factual, history of the Metal Gear saga, and how it started. So with that in mind, I shall expound the true story of Metal Gear.

The first Metal Gear game was released by Hideo Kojima in 1988 for the MSX(a popular japanese computer/console system of the time), and saw huge success in that market. So, it was ported to other platforms, most notable of which was the fledgling Famicom(NES in the states), and brought to the United States by that venue. It was incredibly popular there. The second game, Metal Gear 2: Solid Snake, was again made for the MSX, but was never ported to the NES and brought to the United States. Metal Gear: Snake's Revenge was an American product, made by a developer at Konami's Ultra Games label, the company who owned the American rights to Metal Gear at the time. To this day, Hideo Kojima, the original creator of the Metal Gear saga, refuses to recognize Snake's Revenge as an entity, let alone a playable game (and I agree, it's horrible). Snake's Revenge was an attempt to cash in on the popular US Metal Gear franchise, since it was quite obvious that the real sequal, Metal Gear 2: Solid Snake, wasn't going to make it to the Famicom at all.

So, the only way you can really -ever- play the actual sequel to Metal Gear, is to go and get an MSX emulator and go and play Metal Gear 2: Solid Snake.

Several years later, Hideo Kojima comes along and says "I wanna make a sequel", and he did. A very good one, and hopefully "MGS2 : Son's of Liberty" will be even better. But only time can tell.