The popular music game comes back for an encore!

Despite an expensive $170 price tag, Rock Band quickly became a smash hit among hardcore and casual gamers alike when it was released last November. Harmonix, the developer of the full-band rhythm game, have impressively kept their promise to deliver new downloadable content every single week since the title’s release.

Despite their dedication to viewing Rock Band as a music platform rather than a single game, Rock Band 2 is here. Offering a whopping 84 new tracks (64 of them on the disc) and a whole boatload of new features, it definitely packs a whole lot of punch for the price. Although the PS3 and Wii versions and full instrument bundles won’t be available until mid-October, the Xbox 360 version has already been released.

The most significant overhaul has been given to Band World Tour. The career mode that was formerly only available as local multiplayer is now playable with any number of players (including solo), both locally and online via Xbox Live. The gameplay of the tour is essentially unchanged - earn money and fans playing song sets in order to play larger and more prestigious venues - but the increased number of special events makes it much more exciting. You might be approached by a film director about making a music video, or asked to sponsor a product, or things like that; all in all, it helps to make you feel like you are actually part of a band instead of simply playing song after song.

In addition to touring, your band can also participate in local Challenges and online Battle of the Band competitions. A challenge is, simply enough, a set of songs that you must complete. Beating a local challenge unlocks more challenges. This is the closest replacement for the solo mode found in Rock Band 1 and the Guitar Hero series; instead of playing through tiers of songs, you can pick your favorite instrument (including bass, a welcome addition from RB1) and play through increasingly difficult solo challenges. Local challenges are machine-generated based on what songs you own.

If you have purchased the pack of The Who downloadable songs, for example, you might see a Who Challenge show up. It sounds like a cool idea, but to be honest I wasn’t very enthralled. The basic instrument challenges are the fastest way to unlock songs, but the extra challenges seemed like they were just thrown in. It’s nice that Harmonix included them, but I personally didn’t feel they really added to the experience.

Battle of the Bands, however, is a new feature that adds a great level of replayability to the game. Rather than simply competing against your previous scores in the local challenges, you are playing for fame and glory on the Xbox Live leaderboards. Harmonix updates the game daily with new BotB challenges, and you can compare your best scores with your friends and with the entire Rock Band community.

Some challenges are based on getting the highest score, so having a 4-person band is a necessity, but others are set up so that even solo players can compete. Some Battle of the Band challenges are particularly wacky, such as one recent one that dictated you play a particularly difficult guitar solo on expert and build up the longest chain of continuous notes that you could. As long as Harmonix continues to update these BotB challenges with a regular frequency, they will go a long way towards ensuring that Rock Band 2 is still enjoyable for a long time to come.