PES3 may look like very similar to PES2 at the first glance, but as you get deeper in the game, you realise that the similarities are only skin-deep.
Firstly, the player models have actually been improved. They're more athletic, a bit of a cross between the stickmen of PES1 and the stocky Neanderthals of PES2. The faces have been made more true-to-life, especially for the players playing at the licensed teams(Juve, Milan, Lazio, Roma, Feyenoord, the Japanese and Korean national teams). There is a wider range of animations, though admittedly the standard running animation does look retarded from some angles. Notice that when you are sprinting and try to change direction, the player sticks his inner arm out slightly and swerves his torso so as to maintain balance. This was not present in previous games, to the best of my knowledge, and adds to the realism of the game even more. There are more animations for trapping the ball, and the new flicks and tricks have blended into the game seamlessly without ever making the game look arcadish. Konami have to be commended for that.The number of national and club teams have also improved, and finally Konami have given us an unlockable free transfer option.
The gameplay almost hits the nail on the head in terms of the opposition AI. While in PES1 you would be outmuscled in midfield and in PES2 you could rule the middle but find getting into the penalty area a bit more challenging, in PES3 you have to work harder than ever to get anywhere past the halfway line. Every team plays to a different plan, and in some games you will find it easier to score by stretching the opposition on the wings, while in others you may have to resort to long balls or a more patient, passing game. Your success depends on you playing to your strengths, rather than playing to a 'money-move' - a routine that results in a goal 99% of the time. One gripe with the general flow of the game has to be its pace. It's just a little bit too quick for my liking, though it's not too bad at all. It still feels like a football match, except the footballers have been having too much coffee in the pre-match.
The keeper AI seems to have been downgraded for this version, perhaps because they were slightly unrealistic in the previous versions, pulling off some superman saves. it's a bit too easy to go around a keeper now, but you don't get many one-on-one situations in this game, unless you're VERY good at it, so usually you have defenders in to cover you and throw you off your shot.
That brings me nicely on to the next aspect of the gameplay - the shooting system. Personally, I'm still getting used to the system, because it's so different from PES2. Perhaps it's just me, or maybe Konami have made a fundamental change to the shooting, or perhaps it's just more exaggerated now than it was before. The pace with which the power bar fills up is determined by:
1) The player's shooting stats
2) The player's balance at the time of taking the shot
3) The time the player has had to line up the shot i.e if you're taking a first time shot, the power bar fills up more rapidly than if you have had a lot of time on the shot.
The number of trick moves has also increased. You can fake a shot and immediately chip the keeper, you can use the backward dribble to fool oncoming defenders, the 360 degree spin is in the game, so are nutmegs, jumping over slide tackles, chips, overhead flicks, you name it and it's there. As I mentioned earlier, these tricks do not serve to make the game unrealistic.
I won't waste time on the commentary, only because I turned it off immediately after getting the game, so it would be unfair to comment.