It's hard to talk about Guitar Hero III without also blabbing about Rock Band, but I'll do my best to fight the temptation. We'll save that comparison for when I do a proper Rock Band review. But it's totally fair to start talking about Guitar Hero III by looking back at what I had to say about Guitar Hero II.
As soon as Guitar Hero II landed on the Xbox I was ready for a truckload downloadable content... which never really came. There were 7 track packs released, 4 of which were recycled from Guitar Hero I, and 2 were indie collections that I frankly don't have the patience for (at least not at that price). So effectively there was only 1 interesting track pack… yeah. It's too early to really say whether Guitar Hero III is going to follow that pattern. There have been 2 real track packs so far, which look decent but I haven't bothered to pick them up. Guitar Hero certainly isn't competing well against Rock Band when it comes to either pricing or selection. Instead of focusing much energy on downloadable content they're going to focus on yearly title releases. You're effectively getting one huge infrequent bundle of tracks, which is cheaper in bulk and comes paired with a software update. It's not that bad as long as the selection agrees with you and that gameplay gets refined. So, yeah, how's that gameplay doing?
My main problems with Guitar Hero II were around unlocking stuff for multiplayer and the awkwardness of coop account management. Guitar Hero III has added a coop career that removes the need to play singleplayer in order to unlock tracks. Unfortunately that's the only improvement here. You're still totally boned if you hit a brick wall and need to dial down the difficulty (you'll have to start your campaign over from scratch). And the whole coop career falls apart when multiple Xbox Live accounts are involved. Only one player gets credit for advancing through the career and there's no way to play the career online. There's only enough coop in Guitar Hero III to put a bullet on the back of the box - it's in no way a complete experience.
The other main gameplay addition is the battle mode. A few times in your solo career you go head to head against some guitar legend. The two of you alternate playing ridiculous riffs and try to send bad voodoo at each other at the most inopportune moments. It's generally a refreshing change of place due the objective switch and the nice intricate guitar solos. Your final battle is with the devil himself, who in no way was paying attention to the linear difficulty curve. I breezed through most of the solo career on Hard but failed countless times against the devil. I'm all for a good challenge, but don't be a tease and hold it all off until the end. That's just frustrating.
In multiplayer the battle mode doesn't fare nearly as well. Far too many matches end after the first attack or so. The only way to keep it from being arbitrary is to have both players play on a difficulty far below their comfort level, because lefty flip and double notes on expert is pretty much an immediate game over even if you have your act together.
The achievements in Guitar Hero III are a complete step backwards. I realize I'm an achievement whore, but I seriously deserve more than 15 goddamn points for beating the whole game on Hard. Assuming you pick up a 250 streak and a 250k score, you're looking at a grand total of 35 points. To put it into comparison, Guitar Hero II doles out approximately 150 points for the same accomplishment. Never mind the fact that both games have the brain-dead notion that beating the game on one difficulty doesn't warrant the achievements for the easier difficulty levels. They actually expect you to play through the game on Easy even if you beat it on Expert (which is fun... how?). Okay, so they're not handing out points for beating the game, what are they giving them out for? There are some ridiculous achievements for multiplayer (consecutive wins, are you kidding me?), and a whole bunch for coop which has the aforementioned problem of requiring that you do the whole thing twice if you're dealing with multiple Xbox Live accounts. The real value of achievement points is presenting the player with an interesting challenge that enhances and lengthens their enjoyment of the game. Guitar Hero III just throws a whole bunch of hoops your way, none of which are any fun.
I've been really hard on Guitar Hero III. I fundamentally enjoy the game, but not because they did anything to enhance the experience. I just plain enjoy pretending to be a rock star. The most important thing, the track selection, is pretty good (even if it does break into inane metal bullshit at the end). And the new guitar is nice, although I saved the money and only picked up the disc. I don't completely regret buying the game, because I know it'll get used at parties. But now that I have Rock Band I'm really thinking that Guitar Hero III would have been better off as a rental.