On the 7th of July, 1987, Metal Gear for the MSX2 was released in Japan. The game wasn’t actually all that successful until Konami ported it to the NES and released it in North America later that year, where it went on to sell a million units.
Metal Gear was originally a straight up shooter until Hideo Kojima was assigned to the project to sort out development difficulties. Inspired by The Great Escape, he decided to abandon the game’s focus on action and emphasise stealth.
Konami decided to make a NES sequel, Snake’s Revenge, without Kojima’s involvement. Kojima was allegedly persuaded into making the sequel, Metal Gear 2: Solid Snake by a co-worker who was on the Snake’s Revenge project, who wanted a true Metal Gear sequel.
Neither game did especially well, leaving the series dormant for 6 years until the release of Metal Gear Solid, which turned the series into the powerhouse franchise it is today.
Konami does not appear to have planned any special releases or events for the actual date of the anniversary, though we’ve seen a series of Uniqlo t-shirts and Play Arts Kai figures released over the past 6 months. The next Metal Gear game, Metal Gear Rising: Revengeance, is due out in early 2013.