The visual package is phenomenal. Of course, some games have better textures, or push more polys - but everything blends together so well, that it is hard to fault the game on anything. Sure if you want to be nit-picky and complain about a few minor things (like the collision detection in some areas) go ahead, it's your perogative. But from start to finish it is perfectly clear that Konami, in the words of John Hammond from Jurassic Park, '...spared no expense.' From Snake carefully tip-toeing around sleeping guards to him trying to hang on to a ledge for dear life, the details are there. The amount of emotion they are able to squeeze out of just about every element in the game is great, for example - when you are holding up a guard, you can really tell he's scared. The only thing missing from the picture is a wet patch running down his camouflaged pants. And it's not just the 'vital' movements that got attention, but even the small 'Easter egg' ones, like Snake slipping on a massive pile of seagull poop. To top everything off, the cutscenes dispersed throughout the game could put Hollywood to shame.
The sound is nothing short of brilliant. A sweeping orchestral soundtrack, composed by Harry Gregson-Williams (The Rock), plays throughout the game. Just like a movie, it peaks to a loud exciting tour de-force during intense moments and dies down to barely a whisper during those times when you are carefully sneaking down a hall. For the purists, the familiar MGS themes are present everywhere. Only now, they are presented in brighter, more attractive packaging.
Voice acting has, and will always be a sticky subject matter when it comes to games. Thankfully, the main cast from the original has returned, and a few new ones have joined the fray, making for some top-notch voice acting. There are a few instances where the lines get in the way of believable dialog - but when everything else sounds so good, you can't sweat the details.