There are a number of changes to Madden 13, with there being some for the better and many for the worse.
EA has decided to combine both offline and online franchise, Superstar mode, and Coach mode in to one mode called Connected Career. This allows you to create your league online or offline, allowing you to invite other players in to your league or keeping it solo and playing offline, as well as being a single player(Superstar) or a single coach(Franchise). I have read other players complain that Franchise mode is gone, but it is not. All the same franchise options are available in Madden 13, but under a different name. This is confusing but gamers will eventually figure it out. A big no-no for fans is that you cannot edit players' positions or ratings. Instead, player rating progress can be determined either manually or automatically and on a weekly basis. You gain XP by playing practices as well as in-game performances by the players. This XP can be used towards progressing your players in an RPG like style. You can do it yourself or let the cpu progress them yourself. Also lost in the Franchise shuffle is Fantasy Draft. Although I did not do many Fantasy drafts in the past, I do think it is unacceptable that EA took it out in this year's edition. It was a fan favorite and it will not please players. Online play is still present here either via co-op or versus. Lobbies are also still present but quick play is the only way to play ranked matches. In my opinion, I've experience lag in every game I've played. There's not much of a delay but the frame rate stutters throughout which to me makes online playable. I am doubting it's my internet connection but there's a chance it could be. I am not going to comment on Madden Moments, Ultimate team, or NFL Legend players as I have not played those.
Gameplay: I've always been adamant about EA stepping up their game and focusing more on the actual on-field game play which I believe they did this year. The new infinity engine leaves for a lot more kinds of tackles and group tackles as well as players running in to each other and reacting realistically. Not everything is realistic about the engine however and it certainly shows how raw the engine is. Players will end up in weird positions and fall over each other and even the running backs will in to their o-line and fall down. These faults not only detract from the immersion of the game, but affect the outcome of many plays throughout the game. Whether or not EA will patch the engine in the first update remains to be seen, but I think it'd be a good idea for them to do so. Also new with the gameplay is the ability for defenders to only be able to react to the ball within their vision. If their backs are turned away from the ball, they cannot react to it. This helps tone down the super-man linebackers and create more realistic AI. The passing game has improved and the left analog stick plays a more important role in the direction of your passes. Point the left stick towards where you want it to be placed towards a WR. I wanted to add that currently, stat tracking for tackles is a little glitchy right now. The game does not track assisted tackles, only solo even though there is a category for assist tackles in the game. This to me is an issue that needs to be addressed right away as I like for my players to have realistic stats. Many of past Madden problems still exist here unfortunately and it's not helping turn around the game's legacy of this generation. WR dropping easy balls, user-control over defensive players is still touchy, computer catching more INT's than my players, ineffective play-action plays, hard to control WR's when ball is in the air still exist in this game
Presentation: The game looks fine, but not great. There is a blur-effect that I believe is present to hide the mediocre looking textures of the player models. Grass looks better and the stadiums look good. The engine seems to run smoothly at all times and I think this is a plus considering past Madden games that seemed to stutter a lot. Kudos to the programming team in this respect. I think the game fell behind a step in the sound department. NFL music orchestra replaces a brand new soundtrack in the menus which to me is very disappointing and rather annoying. Keep this kind of music on the field, not the menus. The broadcast team is just mediocre this year in my opinion and the color commentator Phil Simms seems to complain more than praise about on field plays and decisions. They never get too excited over big plays and the commentary overall just feels mediocre. At least they rarely get the things they say wrong, unlike Collinsworth and Gus Johnson.
Conclusion: I know it sounds like I talked more about the negatives than positives, but I still think the game has improved the on-field action for the better, even if the engine is raw. The new features and menus will displease fans, but the game offers a lot more ways to play the game giving you more bang for your buck. Patience is required to fully enjoy Madden 13. Give it a chance and you'll get use to the new changes.