Super Smash Bros spoiled Metal Gear Solid 4
One source states, "Hideo Kojima is the creator of the franchise. He also happens to be a huge fan of the Smash Bros. series. Solid Snake to appear in Melee, but it was too late in development for him to be included. Snake would later appear as a playable character in Brawl.
Snake's inclusion in the game was unusual, due to the fact that most of the well-known Metal Gear Solid games were PlayStation exclusives (at the time). The Metal Gear Solid games also carried adult age ratings. Despite this, Snake became a popular character in Brawl and fans were disappointed that he did not return for the later Smash Bros. games.
When Snake appeared in Brawl, he had his own stage based off of the front of the base from Metal Gear Solid. What most fans didn't realise at the time was that this level was full of spoilers for the upcoming Metal Gear Solid 4: Guns of the Patriots. The Brawl version of the Shadow Moses Island base can break open, revealing Metal Gear Rex battling a series of Gekko robots. Not only was this the first on-screen appearance of the Gekko (who would have a major role in Metal Gear Solid 4), but it spoilt the fact that you would return to Shadow Moses Island and use the Metal Gear Rex to escape from the base. Metal Gear Solid 4: Guns of the Patriots was released six months after Brawl and was a PlayStation 3 exclusive"(Baird).
