You can pretty much sum up the story of MGS like this;
You see, there once was the Big Boss. He was a legendary soldier and he had a brother (now if he owned a brothel, that would be really weird right?). Revolver Ocelot did something, became Liquid (not the kind you will have to mop up later). Something something, a giant metal gear loaded with warheads. Solid Snake comes into play. Raiden is some kind of zombie corpse revived from a FOX-unit as a cyborg ninja. FOX-unit is some secret military ops. FOX-die is some kind of virus to eliminate them. Everyone is a clone of Big Boss, everyone. Because Snake is a clone, he ages very rapidly, see Molly the sheep for explanation.
Nanobots can cure/stop cancer (well duh) and give you immortal life, that's how everyone ever in the MGS-plotline was able to make a cameo in MGS4. Some female scientist made a vampire named Vamp. Vamp gets to fight Raiden, zombie on vampire action if you're into that thing. A lot of cows strolling by while they're fighting. Meryll has the hots for Snake ever since he has seen her in her undies. Now she can bust a cap in everyone's ass. Something about PMC and militias. I don't know what Zero has to do with anything but he's in there. I think he was a communist. Cold wars being fought, apparently the japanese have to step in to save the world from communism. The Cuban missile crisis was done by the Patriots. The Patriots are the illuminati. Something about the Big Boss still being alive, probably nanobots again. Forgot about Metal Gear, I guess that shows up now and then.
I don't know, you're better off learning the anatomy of every living thing that has ever existed in every single languages ever conceived. You never play a MGS for the story. I'm hesitant to call it a story because it plays out like a 72-hour lasting acid trip. Ask yourself this after every line of dialogue, can this be explained by nanobots? If the answer is Yes, you're playing a MGS game and you should accept it as the truth.
In my opinion, it looks to bland. The PS 3-logo, Isaac, some shooter, the OnLive-controller and some picture of a website doesn't give me anything. And a header should give me something. Like the name of the site.