I watch Guitar Hero a little too closely, so my E3 Guitar Hero II experience essentially amounted to a verification of everything I knew already, and as a result I didn't know exactly what to relate. This is why I was glad to have a civilian along for this playthrough, a man for whom our primary means of interaction months on end was a back to back twin guitar assault.

I will tell you things that made him freak out:

a) User selectable difficulty. This is a nice feature, to be sure, and very welcome - but for people who are still playing the original, the lack of user selectable difficulty is a huge stumbling block for Guitar Hero in a social atmosphere. I've been playing it since E3 of last year, I need hard or expert play to even feel it. At the same time, you want to encourage those people who are standing in the doorway because "they don't really like videogames," but for some reason they can't seem to tear their eyes away from this videogame. Guitar Hero breaks those people down and folds them back up, and letting people choose how they want to play just makes it easier.

b) Co-operative mode. We play the battle mode as co-op in GH1, but it's not, and when you play this mode in GH2 you'll see what a gulf there is between them. Not only are you both playing the whole time, a significant departure from the trade-off mechanism in the last one, you each have your own unique part. What part that is depends on the song, and talking with the producer it became clear that whichever part would provide better gameplay takes the fore. So on Kiss' Strutter, you're playing lead and your friend is playing rhythm. In Primus' John The Fisherman, the bass is arguably the entire point, and so it takes the stage. Trading (ahem) "licks" in Texas Flood always had an amazing feel before, but having someone keep the song moving while you tear into a solo (or vice versa) simply trumps it. Add to this that you must both be on your game to maintain your multiplier, and must tilt simultaneously to engage Star Power and you have the raw materials for many evenings shot through with savage rock.

He also liked c) Three Button Chords, but I don't know if that needs a whole thing.