Guitar Hero was not the only rhythm game to release on handhelds. Rock Band, which was riding high with the release of Rock Band 2, was already gearing up for a busy release window. MTV Games was looking to push Harmonix a bit further with multiple releases in 2009, while their publishing partner Electronic Arts was looking to diversify the Rock Band portfolio. In total, Harmonix would be involved in three game releases in 2009, with a little help from a handheld developer for their first release of the year, Rock Band: Unplugged for the PlayStation Portable.
Unplugged is a strange beast, because Harmonix had to basically do something impossible for a handheld; recreate Rock Band. Vicarious Visions was able to do so with the Guitar Hero On Tour series, but it was not without great difficulty. Even their innovations with the game's peripheral were not only hard to get that feel, but suffered from some technical issues and warnings to relax your hands for playing too long.
So what does Harmonix create? It goes back to its roots a bit and borrows from one of its games before Guitar Hero as inspiration, in this case, Frequency and Amplitude. Both games are essentially controller-specific rhythm games, which is a bit less imprecise in the early PS2 era, but within their design, Harmonix saw potential in refining the gameplay with a Rock Band skin.
Rock Band Unplugged has you play as all four main instruments, guitar, bass guitar, drums, and vocals, on a simple track layout reminiscent of the mainline Rock Band games. From there, you simply need to hit button combinations on the PSP to get a perfect phrase of notes. Every time you do get a perfect phrase, your chosen track plays for a set amount of time, allowing the player to switch to a new instrument using the PSP shoulder buttons. Each completed phrase adds to your score multiplier.
Phrases are the key to Unplugged. If you have good timing on say a guitar phrase, you then can switch without penalty to a drum phrase for a song to continue the multiplier. Scores are based on phases, not individual notes, so learning a song phase in Unplugged is what will lead to higher scores. Each phrase of a song is just a small bit of the given song, allowing bite-sized chunks of a full song to be played across all four instruments; the only exceptions being solos, which are automatic for their respected instrument until they are completed. You lose the game in this case when one instrument fails to complete a phrase on a track. Staying on the same track for too long drains the crowd meter for that instrument, which will cause it to fail. Failed tracks lead to a restart.
Incorporating the gameplay elements of Frequency and Amplitude; the multi-track instruments, the use of phrases, and switching between tracks, is all complimented by the relative ease of transition between instruments with a push of the button. Skilled players will be able to cycle each phrase without much trouble, leading to what looks like a chaotic mess on screen if you have no idea what you're doing. In truth, it's almost like a rhythm-based puzzle you have to solve; which phrase nets you the most points or can add to your multiplier.
You also get the Rock Band style with this gameplay loop. Band mates are customizable, though they are of course missing a ton of the more detailed choices in the bigger games. You have a Tour mode, which plays out like your standard venue, setlist, song vehicle that allows songs to be unlocked for quickplay and other game modes. Overdrive, Rock Band's version of star power, can be triggered using the PSP D pad to not only add multipliers to your score, but revives failed instruments if you have been unlucky already.
The only other gameplay modes are a Warmup Mode and Band Survival. Warmup has you play a song normally, with only a currently-selected track affected by missed notes and not being divided into phases. Warmup serves as a 'practice' mode for Unplugged, allowing players to ease themselves into the gameplay loop without much anxiety. Band Survival is the total opposite; Tracks do not play automatically, and the crowd meter for unselected instruments will continually drop, forcing the player to swap between the instruments frequently to keep them alive to complete a song.
All of this is solid work, but there are obvious hiccups to the design. Harmonix was not able to include any multiplayer modes, which means Unplugged is played only through single-player. This is kind of an achilles heel, as the Rock Band franchise is positioned to be a party-based rhythm game versus a singular experience. Unplugged, along with the other handheld Rock Band games that came out for the DS, buck that trend.
Much like the Guitar Hero On Tour games, Unplugged is also somewhat simplified in terms of controls, visuals and song setlist. There are only four note tracks for each instrument. Vocals are done on a track as well, not through actual singing. Drums are simplified without the kick pedal, and guitars and bass have no hammer-on's or pull-offs. This made the songs, for the most part, simpler to play, with the challenge being perfect phrases and switch ins to other instruments instead of challenging charts.
Of course, there are exceptions. Unplugged boasts a solid 41 song setlist in game, which is mostly made up of songs from Rock Band 2 and several DLC released songs. On the one hand this may be seen as a negative; you are not getting any new content, per se, that you couldn't get from Rock Band 2. Guitar Hero On Tour, while it did have repeat songs from previous games, always included some exclusive songs for handhelds that allowed it to stand out a bit.
On the other hand, the different gameplay style of Unplugged versus the mainline series can warrant a new version of the song charts to justify its inclusion. The fact that Unplugged goes for a more puzzle-based rhythm game approach versus a carbon copy of Rock Band, gives it some unique charm all to itself. The chosen setlist is also pretty damn good, with "The Perfect Drug" from Nine Inch Nails, "Alive" by Pearl Jam, and "Aqualung" by Jethro Tull making reappearances. You have Soundgarden, the Dead Kennedys, Boston, and The Killers represented, and Judas Priest returns with "Painkiller", a song that is difficult but a fun puzzle to crack while playing the game.
Harmonix also did Unplugged right with its DLC. The PSP had a lot more processing power, allowing for downloadable content to be more normalized. Through this, Unplugged would be able to bring multiple songs from the already large Rock Band DLC library to the game, with ten being available upon launch and two songs released a week between June to November 2009. Through the DLC, they boosted the number of available songs from 41 to about 100 songs, with all except four of them no longer available on the PlayStation Network.
Rock Band Unplugged is a game that shouldn't work as well as it does. Taking a party-based rhythm game and stripping it of the party is a major hurdle to climb, but those looking for something very different with a Rock Band skin will certainly get enjoyment out of Unplugged. Harmonix was able to find a way to make Rock Band viable on handhelds, much like how Vicarious Visions was able to do it with Guitar Hero. Both had different approaches for sure, but the unique feel of Unplugged, along with the decent support of songs to compensate for a lack of major features, makes it more accessible and enjoyable to play through.