Very few people would argue that Metal gear Solid 4 is not visually impressive; on the forefront of those people is the game's creator Hideo Kojima himself.
In an interview published in the latest issue of the British Edge Magazine, Hideo Kojima was asked if Metal Gear Solid lived up to his aspirations and his reply was that: "Game-wise, it's pretty close to the original vision: you sneak into the battlefield and can choose whether to do a stealth game or interfere with the battle more directly. But the graphic, side things like motion-blending and the size of the map, totally was not accomplished to my original vision - to my satisfaction."
According to Kojima, back when Playstation 3 was first announced, it was a "dream machine" which inspired them with lots of ideas, but "when we actually started developing the game, we realized there were a lot of restrictions and so it turned out how you see it today. The original vision was to go ten steps further; the reality was just one step, which isn't to say we didn't progress."
"I remember saying three years ago that we wanted to create something revolutionary, but in reality we couldn't really do that because of the CPU" Hideo Kojima concluded. "We're using the Cell engine to its limit, actually. Please don't get me wrong, I'm not criticizing the PS3 machine, it's just that we weren't really aware of what the full-spec PS3 offered - we were creating something we couldn't entirely see."