yeah i've been playing on the PS3. Game is tight!!
So, the first thing to know is
this is the early build of the game, EA confirmed this. So the main thing you'll notice is the torso's of both pacquiao and hatton being to big. They fixed that, all the new videos you see they fix that problem. Also they toned down the players faces, in the demo they look too "mean" or whatever.
As far as the gameplay, it's very fast. Much faster and smoother than FN3.
The main thing is the game physics. The best I've seen in a game. Things like getting your punch caught in your opponents arm or under his arm, shit like that happens and you'll really appreciate the physics. You simply don't see anything like that in any other game.
One time for example ricky hatton swung a hook at me and it just grazed the top of my head, his arm then looped around the back of my head/neck and he pulled me in towards him and while I was being pulled in I landed an uppercut on his jaw. Here is a pic I took in instant replay:
The controls are a lot different so it's difficult for me right now, but I'm started getting the hang of it. Body punches you do by flicking the joystick down.
Also, I absolutely suck ass at the new bob & weave system. It will take a while to get that down, but it's a great feature in the game.
Overall the game play is dope and the final version will be better too.
The demo is limited on what you can do. You cannot change the difficult settings (its on easy). You start off by doing some basic training and the fight is 3 rounds. The instant reply is awesome (in the retail game you can save and upload your replays). When you win a decision the demo just announces the winner, in the retail game it's more dramatic, etc.
The punch stats after the fight are also very detailed, much more so than in previous versions.