I was at the Gamescom 2011 in Köln (Cologne) and...damn so many people!

Anyway, I'll skip through all the stuff and go right to Mass Effect 3. Normally you had to line up for up to 6 hours (thats what was written on the plate at the end of the line. Luckily I got a fastpass before I went to the Gamescom so I only had to wait 30 minutes to get in the ME3 Area.

We were shown a 5 minute trailer which was cut together from all the existing trailers (no new material, sadly).

[MIGHT CONTAIN MINOR SPOILERS]
After we saw the trailer, they FINALLY let us play the demo. I was playing the xbox version, and I sucked at it (I'm a PC-Gamer). It was the mission you saw in the gameplay trailer. Mordin rescuing the female krogan.

At the start of the demo I was able to choose between 3 classes (but I think there will be all classes in the finished game). I chose the soldier class, because I prefer to play the soldier class, and it's the allrounder in any situation.

The first thing I noticed is the skill system. They were trying a balancing act between the ME1 system and the ME2 system. The soldier class had six or seven skills/attributes to skill out. I'll name those I remember:

-Soldier general class attribute
-Incendiary Ammo
-Disrupter Ammo
-Adrenalin Rush
-Concussion Shot

The skill system looked like the one in ME2 but when you chose a skill/attribute, it opened up the path of it. There were 3 basic points you could skill (mostly increasing damage / duration). When you skilled that 3 points the skillpath split up into two paths. I'll explain it with the example of Adrenalin rush.
You could decide between more increased duration / slowdown or reduced cooldown time. If I had seen it right, I could skill both paths though...if you have enough skill points. Oh, and the interface of the game is lightblue again - like in ME1

I wasn't able to get a look at the dialogue system since there were only cinematic scenes and fighting in there, but I guess it didn't change since ME2.

The squadmates provided were Liara and Garrus. (They didn't say anything about the other ME2 squadmates)

Oh, and the weapons on shepard were a bit different from ME2. The soldier class Shepard got a M-3 Predator Pistol, a M-9 Tempest SMG and a M-96 Mattock Assault rifle. The weapons handling "felt" as they were directly taken from ME2. No shocking changes there. Shepard had no Heavy Weapon there though. I don't know if it was just in that demo, or if that will be the default in ME3.

[FROM HERE ON I'LL RETELL THE MISSION - DON'T READ IF YOU DON'T WANT TO KNOW WHATS HAPPENING - JUST SKIP DOWN TO THE "NO MORE SPOILERS" PART]

It started with Mordin with the female krogan (who was in some sort of containment pod) in a container with a barrier. Once you were done talking, the container started moving to the next area with Cerberus Agents dropping in, so I had to fight my way through.
The AI of the opponents, aswell as your teammates was improved quite a bit. They moved into good spots and focused on weakened enemies. Also when an enemy was trying to circle around and attack my flank, Garrus was always there keeping them down. Liaras Singularity was a great help with the shielded agents.
A thing that changed pretty much was the melee combat. Shepard had different attack moves that stunned/immobilized the enemy long enough to land a second punch. As far as I could tell Shep had a 3 hit combo. If I you "charged" the melee attack, Shepard was using his omniblade. (If every class can use it, or if it is a soldier only weapon, I don't know. I was too busy playing myself to check the other screens )
I wasn't able to kill an enemy with it though, since Garrus picked them off before Shepard was done with unfolding and getting in position with is omniblade. (I was playing on normal)
Garrus and Liara were keeping themselves in the background, so I had to do most of the fighting, but they sure were more useful than targets to shoot at for the enemies (like in ME2 )

The health system is pretty similar to the one from ME2 (no health bar). A difference was, that the shields and health took a lot longer to recharge (or at least it felt like it).

So, back to the "story". After fighting through some waves of enemies, I got another cinematic where the female krogan asked why Shepard was helping her. There might be some krogan love later one from the lines I remember:

K: "This isn't your problem Shepard! You don't know me!"
S: "But I'd like to."

Oh! And they were mentioning Wrex. So if he survived ME1 with your Shepard, he might be joining your crew - or at least he gets a "guest appereance" on that mission. I didn't see him, but he was waiting outside at the shuttle.

The rest of the mission was kind of...standard. Reset a power junction...protecting the container with the female krogan.

Just when the Atlas mecha made it's appearance I was told the time was up.

edit: Oh! I just rembered. Shepard talked with Mordin about the Cerberus Agents attacking him. It seems Cerberus got indoctrinated somehow (either by another reaper they found, or the (not) blown up base.) They didn't go deeper if the Illusive Man was at fault, or if this was/is only a faction of Cerberus (remember, they work in independend cells).

[NO MORE SPOILERS]


Arrrrgh...damn it... I wanted to fight against it so badly...but ah well. Before we got out of the ME3 area we all were given a large poster and an inflatable omniblade xD

Well thats it. That was me playing like... 15 minutes playing ME3. I'm sure I left out some important infos are I wasn't detailed enough about something. If you want, you can ask me anything and I'll try to answer it as best as I can

edit: I just remembered, I forgot to write, that modded romances (on the PC version) won't be able to go on. It was quite clear that it wouldn't be possible, but well...we got the "no" from an official.

Also the question was asked, if we are able to see other races females. The developer couldn't or wouldn't answer this question, so maybe they have some aces in their sleeves