At the end of the game Snake is given the title "Big Boss" for defeating someone O_O which you'll find out, unless you want me to spoil it for you.
I would have to say that Konami got really bored half way through the game so they added a "View" for Snake, which is actully cool in some scenes you get to see awesome things. And then there's Eva scenes or should I say "Eva" (You'll get the joke when you play the game >.<)
THey made it so Eva seems to be half naked throughout the entire game, which is unnessacry but i'm not really complaining ^_^
The game is awesome, but too short. You kill the Cobra unit in like 50 minutes, which seems long but it's not. Games are suppose to last days not hours. You kill cobras in this order:
The Pain
The Fear
The End
The Fury
The Sorrow
I can tell you which one is the easier, The Sorrow, you just die... and then you beat him. Very dissapointing, he's so cool yet his battle he doesn't attack, he just flaots down a river and throws these scary nightmare attacks at you which do like .0000000000001 damage.
Theres a new system to MGS3 which is healing yourself, Stamina is in the game, when you lose Stamina eating something will get it back up. Healing yourself is actully cool, if you get a gunshot you open up the menu and apply nessacry things to the wound to heal it (Takes about 3 seconds once you memorize what to do for each wound)
I would give MGS3 a 9/10
This game is great for renting but when it was gone I missed it

I loved the story so much and I didn't even play MGS1 and I never finished MGS2 (although MGS2 was awesome, except Ridien... what an ass)
Actully now that I think about it the only hard part of this game was the boss: The End. Yeah he's old and crap but you have to sniper war with him. YOu fight in this huge area, he's practically invisable and you have to look around and shoot him before he shoots you. Takes like a million hours to finish.
If you rent it I suggest you play it on Normal or Hard mode to make it last longer, on easy it goes by too quickly.