My impressions (Heisman Difficulty):
The Good:
Graphics
Presentation
EA Sports logo (apparently this makes the difference)
The Bad:
Passing game is still too easy.
Flats are easy to abuse
Post routes are still overly effective
Overall you can squeeze the ball in places you shouldn't be able to, and complete passes that would hardly ever be made in real life.
Unrealistic stats and feel to the passing game.
QB drop-backs and planting isn't there/unrealistic
Horrible blocking logic.
Specifically the WRs. They're hesitant, indecisive, and time and time again will fail to pickup the obvious assignment. I've noticed WRs go after one defender, just to change their mind midway, then go after another. By that time I'm tackled and that specific WR hadn't gotten a hand on anyone. This was also a reoccurring problem on both titles last year.
No realistic double team blocking.
No chips or shoves. They have to be face to face in order to engage in a block, which also makes the blocking horrible and unrealistic. Sometimes all you can do is push a guy out of the way, but you don't see that on this game.
Route running is not realistic. You don't see WR's plant and cut like they should, you also don't have any visible difference in route running between any of the WRs.
Cookie cutter defenses. You can't scheme by disguising your coverages, changing your shells, call delayed blitzs, etc (ala 2k8)
No bull rush and unrealistic play in the trenches
Too much time in the pocket.
Goofy defensive line play. I watched 3 D-linemen fall flat on their ass, all at the same, all exactly after the ball was hike, multiple times. Often happened back to back. wtf is that? Makes me feel that some of this stuff is fixed, because all 3 linemen can't fall flat at the same time, over and over coincidentally.
Player momentum isn't very realistic, should have been improved by now.
Too easy to return kicks.
That's all I can think of right now off the top of my head. But, it's only a demo, so we'll see how the final version turns out.