Line Play
I'm going to echo what some have said here. The rate at which the OL puts the DL on their backs is beyond unrealistic. Furthermore I've seen many of the animations for the pancakes completely match in both trigger time and the animation itself. It's strange to see 2-3 DL go down at the same time in the exact same way. That in particular doesn't happen SO often, but it's still an issue. Also, the D-Line seems to only get decent pressure when you use finesse moves rather than power. I wonder if this takes into account the mismatch in strength and the various ratings involved in DL vs OL interaction. I'd be interested in some in-depth info on this subject.
Repeat Animations
I've also seen multiple instances of players doing identical TD reaction animations in the endzone at the same time. In 6-10 games I've seen it 3 times.
Offense
The rate at which the OLs in the demo pancake defenders is downright unrealistic, in my opinion. Also, whatever's controlling how and when the CPU QB scrambles seems a little off. I've seen QBs sit at the LOS with 10+ yards of open field in front of them, and some eventually eat a sack. I'm a Bama fan and even Greg McElory, the Ginger Ninja himself, knew when to take off. On the good side, I like seeing the CPU throw the ball away when nobody's open rather than taking a coverage sack. Still, the mechanism that decides how and when one happens vs the other doesn't seem consistent.
Defense
I've seen people mention that they think passing is difficult. I agree but as a personal preference I like it. Still, I think this may lead to cheesing as people try to find exactly what works and what doesn't.
I'm LOVING that we can now get pressure up front. On Heisman I haven't seen the "Garaunteed sack" on blitz plays.
I've seen players bite on play action as well as different types of routes intended to fake out a defender. I actually saw a blitzing LB fooled for a second on a play action, which was GREAT! However agility seems to be an issue as it only took him another second to turn around and waste my QB.
Along the lines of movement speed with regard to DL and LB's, it seems that the closing speed of some DL and LB's is unrealistic, but that could be due to settings in gamespeed and all that. I'm interested to see what the retail version has in store on that front.
Also worth noting that I LOVE the fact that I feel under so much pressure when trying to throw. Getting sacked so much at first has gotten me better at making reads and getting the ball out quicker. I love having to react instantly to a blitz. I love having to adjust to how the pocket forms around my QB, as much as I've loved noticing the CPU QB adjusting to pressure, moving up in the pocket, and scrambling. I love that I can't sit back in the pocket for much more than 3-4 seconds.
Graphics
I've played on the PS3 as well as 360. I haven't particularly noticed the difference in graphics, but I'll take some peoples' words for it. The 3D grass during replays and highlights is nice. It was a good aesthetic touch and really makes a difference in overall experience. I actually noticed the pylon physics at a point I didn't expect to. Again, a nice little touch. I hope, however, that the field texture that shows during regular gameplay can be touched up somehow. Of course I don't expect full on 3D grass all the time, but the current field leaves a little to be desired.
Atmosphere
Crowd noise is lacking, but I think I've noticed swelling on big passes which is awesome.
However, crowd noise overall seems to be lacking. People have attributed that to the fact that this is a demo, compression, etc. which I want to believe. The intros also look good, but I wonder how many people are skipping them. I am. Then again, if BAMA had a custom intro I'd watch it every game. Need for and usefullness of this feature is in the eye of the beholder I suppose (Texas fans, Auburn fans, etc).
Summary
There are things that people have complained about here that I haven't seen. It seems we're either getting a varied experience overall, or some people are overstating situations.
Overall I believe EA has a solid product here. They took many good things from NCAA 11 and expanded on them. Furthermore, the greatly reduced suction seems to have really opened up the run game as well as punt/FG blocks and establishing solid QB pressure. Still it's worth nothing that some of the "dive tackle" animations will trigger suction sometimes.
Regarding suction, I can't count how many times I've gotten that "I'm about to get tackled/suctioned" feeling, to be pleasantly surprised when it doesn't happen! Though it's still not perfect all the time, it's a HUGE step in the right direction and a definite game-changer! The run game is so much more fun.
Passing has become more difficult, and pressure on my QB feels as though it's been ramped up. I find this fun and challenging and have so far adapted okay.
I just wish that when the QB got hit the ball didn't flip out so much as incomplete when it appears or would realistically appear to be a fumble.\
I'll be buying this game. Some say it feels more like "NCAA 11.5" because of how things have been tweaked and improved. It seems like little has been done in this regard. I feel I have to disagree because of the effects the changes have had on gameplay overall. Many things feel different, regardless of HOW much was done to change them. The improvements made were needed and have made a difference in a few ways. This to me justifies purchase. For some people to say "These things should've been implemented into NCAA 11" is irrational. While that may or may not be true, the fact remains they weren't. The changes made and implemented in NCAA 12 have made the game play better, look better, and feel better. While it may not be a MUCH different game, it's a different game and the gameplay experience will be different on the whole.