Great.
The gameplay is solid. Difficulty is very hard. It is much harder than the other two games in the series, mainly because of the songs. Songs like Raining Blood, Through the fire and the flames and One are all fast metal songs and you will probably get really frustrated attempting to play 'Mosh 1' and 'Fast solo A' over and over. It is probably harder for me being a guitar player, because I know how to play some of the songs in the game on a real guitar. Sometimes (at least on easy, medium and hard) the picking is different than on real guitar (it will leave out a note or two so its easier) and I mess up. But once you manage to nail that one song you always have trouble with, you can go back and say 'THAT was hard?'. You can be helped along by star power which you can tilt the guitar upward to activate. Some notes in the song are replaced by star power notes where you can collect it. Once you've lit up 3 tubes you can activate it. This multiplies your multiplier by 2 so you can get more points. This helps you not fail during hard solos etc.
There is a new 'battle mode' that can be played online and this is actually pretty good. Basically, star power is replaced by a bunch of powerups which you throw at the enemy by tilting the guitar. You have to make your opponent fail to win. It is over pretty quickly, especially online where you pretty much need to get 3 powerups, hit the guy with them on a fairly hard spot and then hope they fail, all within the first minute of the song. In the career mode, theres 3 battles against Tom Morello, Slash and the devil. The songlist is great, ranging from the Rolling Stones to Muse, from Slayer to Santana, and it is obvious the developers have tried to appeal to everyone. As usual, you will have some songs you know and some that you really really like but never knew about till you played the game. The third installment in the series has more master tracks (the actual songs) so it sounds a lot better. Unfortunately they covered another Black Sabbath song, and the voice is almost as annoying as War Pigs in Guitar Hero II. Most covers are pretty good though - I didn't realize some were covers until I saw the 'as made famous by' on a second or third playthrough.
You can select just over 10 different characters. You can unlock some of those in the store. In the store (GUITAR CENTER!!!!!!!) you can buy videos of behind the scenes footage, costumes for your characters, different guitars and finishes, and bonus songs.
Graphics are OK. The models all have good animations and the lighting effects are pretty good, but the creators could have pumped a bit more out of the graphics. Mostly though, you will be looking at the fretboard and won't see the little characters dancing. What is annoying is that occasionaly, with some of the wierdly shaped guitars you can select, is that the neck of the guitar will be a little bit under their hand, so it can look pretty glitchy. Also, the developers decided to give every character telekenesis, because there is no strap on any guitar so it just hovers there. Come on, a strap is not that hard to do!
The game has an RRP of £70. This is pretty steep but the game would be nothing without the guitar controller.
The guitar that you play with is a *BUYNOW*GIBSON*BUYNOW* LES PAUL *THE GREATEST GUITAR EVER*. It is sturdy and you can now remove the neck to put it in a bag if you want to transport it. It feels a little better than the SG controller from Guitar Hero II. You can get quite sweaty when you are playing your Gibson(TM)Les Paul(TM). I recommend Axe(C)(TM) deodorant to keep you fresh.
Another peeve is that the game chucks advertisements at you. You pretty much have to play Gibson guitars although there are a few from other companies too. You have to play in bars with 'Axe' people dancing. Its pretty funny that they kept this brand in outside of America, because they couldn't even be bothered to change it to the UK brand 'Lynx'. You must buy from Guitar Center, too.
Overall though, the game is great. The gameplay is addictive and although it is absolutely nothing like real guitar, its still an excellent concept that is well executed.