The rumors that Metal Gear Solid 4 is going multi-platform have been swirling around the internet since the mid 1940s, but, according to Konami, it's just not going to happen. The game will be playable only by Sony fans.
A Konami spokesperson told thegamereviews.com: "For the record, Metal Gear Solid 4: Guns of the Patriots is a PlayStation 3 exclusive and there are no plans to develop an Xbox 360 version of the game."
But still, it could happen, right? In other words, while it's highly unlikely that MGS 4 will come out on the 360, it's still physically possible, and in an infinite Universe, anything that isn't impossible is happening right now, has always happened and will continue to happen, so we are forced to conclude that Metal Gear Solid 4 has always been available on the 360.
We're playing it right now on the 360 in our imagination, and it's awesome!
thegamereviews.com: Metal Gear Solid 4 Guns of the Patriots

