Last year, Harmonix unleashed a beast on the United States gaming world with the critically acclaimed Guitar Hero. While many Japanese companies have turned a blind eye to bringing the addicting rhythm game genre to the U.S., Harmonix gave domestic gamers yet another blessing with an exceptional successor to the Amplitude/Frequency franchise. And, now, exactly one year after the release of Guitar Hero, the inevitable part two descends upon the Playstation 2.

Not content on merely resting on the success of Guitar Hero, Harmonix has gone back to the drawing board, surfed through numerous player comments through polls and forums, sought even more music and the result is more than a mere song update. New game play modes, a new, massive song list, an updated career mode, a training mode, game play mechanic tweaks and more give players looking to grind the axe quite a package.

The most notable addition to Guitar Hero II is the new co-op mode, which allows a second player to tighten the guitar strap and lay down either a bass or rhythm track depending on the song. While some of the songs don’t offer a whole lot of opportunities to showcase the bass parts, the mode definitely brings more “band” atmosphere to the game. Some of the bass tracks are borderline tedious and lacking compared to the riveting solos performed on the lead guitar, which may lead to a few arguments over who gets to take center stage.

Friends can also throw down in the game’s battle mode, which breaks up pieces of the songs in back-and-forth battles where only one can walk off the stage as the winner. However, this mode only shines with players of equal skill. While the game bases performance off the percentage of notes effectively hit, battles don't feel heated or look appealing when an expert player is moving their fingers at mach speed while a medium player is hitting one key at a time.

As fun as the two-player rockfest is, though, online features are still sadly missing. Once the Xbox 360 version hits the scene, players are most definitely going to be drawn to the new downloadable content and the lack of online features for the Playstation 2 version will stick out like a sore thumb.

Given the success of the first title, Harmonix, naturally, was able to go after more licensed songs this time around and more notable bands including Aerosmith, Kiss, Rage Against the Machine, Kansas and more round out yet another solid track listing. Some players might question the song choices picked out from certain bands for the game, but Guitar Hero II represents more of a song style variety in the licensed tracks compared to the first title, most notably in the area of heavy rock songs that feature mind-numbing guitar solos.