So yeah guys, I just finished playing the demo... not impressed.  Lemme break it down.
 
The punching system is similar to that of Fight Night's, where you have to use the right stick for striking. However, pressing L2 and letting go of it back and forth feels to clumsy to be switching from punching and kicking. Also, with the use of the right stick, I find it really easy to go mess up a punch or kick. God forbid I rotate 3/8 of the stick and accidentally to a uppercut instead of an overhead right. 
The fighter's animations when striking just look downright clumsy and cartoonish. They took WAAAAAAAAAY too much of Fight Night and put it into this game. 

The takedowns are even more cheaper than UFC2010, you just press spam the X (A) button to takedown and improve your position on the ground. Although it was really robotic, I like Undisputed's system better (not saying I like it that much). To defend you have to react in the 2/100 of a second a guy shoots for a takedown and press the O button. It's really flawed. 
People were complaining that the clinch and ground systems of Undisputed were too complicated and unrealistic. While EA certainly has gotten the looks of the clinch and ground game down (it's really impressive, it looks like the fighters are actually grappling with one another), there's no mastery to it. Just spam the X button and watch your stamina.  
The clinch system is basically the same, just press triangle.  
Now what has me miffed about this button smashing system is that when on the ground or clinch, people just focus on hammering the X and Triangle buttons till they get the Muay Thai clinch or the Full Postured Mount. THEN the one-sided ass whooping occurs, easily leading to a KO.
 
After playing this, I'm worried about the future of MMA games in general. UFC was just too robotic and broke everything down too much, and while EA's MMA has improved SOME parts of the UFC game, it's far from the ideal MMA game. It's a close tie in between the two and for now I can't decide which one's better. Well, probably not better, but rather which one is worse.

What this demo has proven to me is that no matter how much I love MMA, I will never find enjoyment playing any games associated with it.

well you can change the controls so you don't use the stick to punch/kick.  The takedowns are no different than UFC 2010.  Cept instead pushing a stick forward you are pushing a button.  I don't get why people are complaining about that and comparing it to Undisputed when it is absolutely no different.  To defend the takedown you hit one button....in Undisputed you hold a stick back.  Except EA MMA is better because it takes out the shining struggle part which is completely stupid.

My demo impressions: It sucks. Buy Undisputed instead.

I hear the demo was the pre-alpha phase of the game, but I could be mistaken. Why would they release an unpolished demo? 
@handlas said:

" well you can change the controls so you don't use the stick to punch/kick.  The takedowns are no different than UFC 2010.  Cept instead pushing a stick forward you are pushing a button.  I don't get why people are complaining about that and comparing it to Undisputed when it is absolutely no different.  To defend the takedown you hit one button....in Undisputed you hold a stick back.  Except EA MMA is better because it takes out the shining struggle part which is completely stupid. "

If I were to review this demo, the title of the review would be:
 
EA Sports MMA: The Opposite of Exciting.
 
Now I'm not big on sports games.. I have a mild interest in UFC and MMA in general, in that if it's on TV I'll be happy to watch two guys punch off for an hour or so..
 
But jesus, this game runs at about a quarter of the speed and excitement of real MMA. I'm punching off with a dude and getting little to no response, this game is missing some UH UH UH, UH.
 
Playing this game just made me want to go back and play Fight Night, from memory, it looks better, it was more exciting, and the slow mo replays were heaps awesome to leave on the screen after you beat your mate or vice versa whilst scream YEEAAAHHH MOTHER FUCKER.
 
Maybe I should just stick to shooting guys in the head and building SCVs.

The game is pure crap.

I was literally yelling at my tv. the computer just kept shooting for take downs. I wanted to knock the guy around a bit so i would get on my feet and throw a few punches. but before i could do any real damage he took me to the ground. Must have got taken down at least 50 times in the 3 round match. 

I didn't feel like i was doing any damage to the other player at all. Even a kick to the face seemed to do nothing to him.

Didn't really enjoyed the demo. The striking was poor and I feel like I was doing no damage to the other player. I throw about 300 punch s and  200 kicks and no real impact to the other player. The game seams to be based submission move as that was the only takedown that worked.  
 
Very poor when you compare it to the visceral nature of UFC. I love in UFC that if you got two or three good punch's the opponent could hit the deck.  Not a massive MMA fan but definitely not getting this. Might pick up UFC on the cheap instead.

" My demo impressions: It sucks. Buy Undisputed instead. "

Hmm, I really liked it alot more than the UFC series. 
 
The only thing that bottered me was that I found no way to block low-medium attacks

" Hmm, I really liked it alot more than the UFC series.  The only thing that bottered me was that I found no way to block low-medium attacks "

" @floodiastus said:

" Hmm, I really liked it alot more than the UFC series.  The only thing that bottered me was that I found no way to block low-medium attacks "

me as well.  Tho I couldn't really see much difference from one fighter to the next (I only tried Mayhem and Overeem tho).  Anything is better than Undisputed tho....anything at all. "

I think Undisputed flows better and is way easier to get into. EA MMA, I just walked away from it, after Lashley took me down for the 1000th time, at least standing up in Undisputed is an option and is fun (and EA.. Throwing kicks with the right stick?.. WHY!?). 
 
I think EA MMA is a good base, but I think I'll stick with Undisputed

I think EA MMA is the superior game. BY FAR.

" I think EA MMA is the superior game. BY FAR. "

" @JJWeatherman:  Well, to me the striking is more complete, distance and angles are important,  this is in my opinion one of the reason why the transition from the undisputed  franchise and EA mma is so hard to make.  It took me a few days to understand this.   You can slip punches,  If you want to slip a punch you need to time it perfectly and predict if he'll throw a right or a left. I feel the sway system is more defensive than offensive which is true to the sport, of course you can attack from a sway, but if you spam attack from sways you'll get countered hard...  JABS ARE EFFECTIVE. You can drop someone with a jab. You can also damage your opponent with leg kicks,  you don't need 80 legkicks to see a result.  the physic, the animations, the awesome looking k.o's are amazing. The ground game feel more organic to me, Undisputed 2010 has turned into a reversal contest, in ea mma, you need to work for positions. You can only reverse major transitions, so a reversal can only happen if your opponent take a chance, i like the risk/reward concept which is present in both the standup and the ground game. Submission mini-games are contextual and add to the experience. No need to shine my controller to dust, timing and precision is way better than a circular motion to me.    Sure you can bumrush your opponent and get lucky even on legend difficulty , but if you try to set your strikes up,  dodging at the right moment then you land that big combo you were looking for and not only you pull it off but it ends the fight. It's extremely rewarding to me.  This is why i think EA mma is the superior game. It is an opinion and you are free to have your own.  Try to play Overeem vs. Overeem on legend difficulty. You might get a better taste of the standup.  "

• Even if you're blocking, strikes are still getting through, and you can easily knock anyone out if you're blocking while other people are wailing on you, and while it's realistic, it makes most fights end within two minutes in the first round (when fighting against human opponents).
• Fighters should have a better chin. When me and my buddy were playing last night, if one of us weren't rocked within the first 30 seconds, we just plain weren't connecting with anything.

" @troma said:

" @JJWeatherman:  Well, to me the striking is more complete, distance and angles are important,  this is in my opinion one of the reason why the transition from the undisputed  franchise and EA mma is so hard to make.  It took me a few days to understand this.   You can slip punches,  If you want to slip a punch you need to time it perfectly and predict if he'll throw a right or a left. I feel the sway system is more defensive than offensive which is true to the sport, of course you can attack from a sway, but if you spam attack from sways you'll get countered hard...  JABS ARE EFFECTIVE. You can drop someone with a jab. You can also damage your opponent with leg kicks,  you don't need 80 legkicks to see a result.  the physic, the animations, the awesome looking k.o's are amazing. The ground game feel more organic to me, Undisputed 2010 has turned into a reversal contest, in ea mma, you need to work for positions. You can only reverse major transitions, so a reversal can only happen if your opponent take a chance, i like the risk/reward concept which is present in both the standup and the ground game. Submission mini-games are contextual and add to the experience. No need to shine my controller to dust, timing and precision is way better than a circular motion to me.    Sure you can bumrush your opponent and get lucky even on legend difficulty , but if you try to set your strikes up,  dodging at the right moment then you land that big combo you were looking for and not only you pull it off but it ends the fight. It's extremely rewarding to me.  This is why i think EA mma is the superior game. It is an opinion and you are free to have your own.  Try to play Overeem vs. Overeem on legend difficulty. You might get a better taste of the standup.  "

Agree 100%. There are only a few problems I have with the game: 

• Even if you're blocking, strikes are still getting through, and you can easily knock anyone out if you're blocking while other people are wailing on you, and while it's realistic, it makes most fights end within two minutes in the first round (when fighting against human opponents).
• Fighters should have a better chin. When me and my buddy were playing last night, if one of us weren't rocked within the first 30 seconds, we just plain weren't connecting with anything.

 
I'm not sure if these are results of both of us changing to "Classic" control mode (face buttons for punches and kicks), but either way, it was a little ridiculous.
"

hundreds of AI bugs have been fixed.
takedown frequency has been reduced.
adaptive tendencies have been improved.
We've fixed the defensive exploits with the spamming of body shots on the ground.
The career mode AI is very diverse so like someone pointed out some AI won't even go for takedowns.
We can update AI online.
Expect a more refined, intelligent AI in the final version of the game both in fight now and in career mode. 
 

I didn't care for it. 
I never thought i'd take a THQ game (gameplay wise) over an EA game, but this would be a first.

Not until I played this demo had I seen a computer man so desperate to throw me to the ground repeatedly and grind his man bits on me.

I've downloaded the demo weeks ago, however I didn't play it. Now that I seen the quick look on this site, maybe I should give it a try, I was expecting a really terrible game, however it looks like a decent MMA game.