In a move to make the game more party-friendly than GHWT from the get-go, Neversoft has thoughtfully unlocked every song on the disc in Quick Play mode; playing through career mode is mainly about unlocking items and the overall Metallica "experience." Which, as we found, starts out by having you play a couple of songs by the metal legends then becoming so inspired that you start your own band (who you play the games non-Metallica songs as).
The other bands' tracks have all been selected by Metallica because they've either influenced the band or are simply personal favorites of its members. The band's say concerning what songs get to be "in" Guitar Hero: Metallica even extends to DLC. First, there won't be any DLC release for the game. Secondly, the only Guitar Hero: World Tour DLC that's compatible with it is Metallica's own Death Magnetic album. (It's not included on the disc.)
In terms of actual gameplay tweaks, Neversoft has placed individual performance / star power meters next to each instrument's note path, making them much easier to keep an eye on. It has also implimented an FPS-style red "halo" around the screen in the event that the entire band's in danger of failing out.
Don't get us wrong -- a lot of effort has clearly gone into making the game scream "Metallica!," from its historic venues and background tidbits to the on-stage showmanship of the band itself. Who knows, it could even bring some new fans into the fold. As with Guitar Hero: Aerosmith, however, it has us concerned Activision's milkmaid will soon be out of work.