The Bit.Trip series does a nice job exemplifying what Nintendo's WiiWare download service should be: a consistent source of cheap, yet innovative games created by small developers. Released four months after its predecessor, for the same six dollar price tag, Bit.Trip Core is also a perfect example of a good sequel, as it offers a completely new experience while retaining the same retro style and rhythm-based gameplay concepts introduced in Bit.Trip Beat. Also the sign of a good sequel, Core offers a more challenging and, consequently, more rewarding experience by giving players more direct control over the rhythm.

Bit.Trip Core continues the story of Commander Video, a mysterious spaceman searching for the truth behind the connections between rhythm, technology, and life. While Bit.Trip Beat featured large planets and comets in its retro backgrounds, Core features complex technological landscapes, all highlighting Video's ongoing quest. The plot is practically nonexistent except for brief cutscenes before and after each level. There isn't any dialog and there's never any indication of what's actually going on, but the plot does its job while never getting in the way by adding to the game's bizarre, trippy style.

At the end of each stage, boss battles test the player's reflexes in three waves.

As in Bit.Trip Beat, the object of Core is to prevent as many Beats (flying pixels with various properties) from escaping the screen. Players control the Core, a red plus sign in the center of the screen capable of firing a beam in the four cardinal directions. Aside from a few of the trickier Beats, anything in the path of the Core's beam is instantly destroyed, earning the player energy for the Mega Meter. Filling the meter elevates players to higher modes, allowing them to survive longer and earn more points. Conversely, any beats that manage to escape add to the Nether Meter, which, when full, demotes the player a mode. When a player is demoted from the default mode, the music fades and the screen turns black and white. The only sound at this point comes from the Wii remote's speaker. This sudden transition from pumping techno rhythms and colorful flashing scenes to a dull background and relative silence can be a bit jarring at first, but it's still a neat effect. Adding to the tension, filling the Nether Meter in this mode spells game over.

Each of Core's three levels consist of eight sections. Beats fly across the screen in various patterns according to their color and shape. Each Beat the player destroys adds another note to the stage's chiptune soundtrack, and the sounds get louder and clearer in higher modes. While still requiring the quick reflexes demanded in Bit.Trip Beat, Core also demands a great deal of memorization from players. Each stage takes over ten minutes to complete, but the game's difficulty starts off steep and escalates from there, so completing a stage could take many tries. It's easy enough to remember what specific Beats do after encountering them for the first time, but the patterns they come in demand close attention and anticipation.

The Beats range from simple yellow Beats, which never stray off course once they enter the screen, to blue Beats, which explode into more Beats upon being hit. Others include flashing green Beats, circling purple Beats, swaying turquoise Beats, bouncing orange Beats, and many more. The unique white Beats return to offer power-ups and challenges including a beam that allows you to fire in two directions at once or constantly in one direction. Combined with others, the Beats can form complex patterns that appear daunting when they first fly onto the screen, but Core's heavy emphasis on rhythm serves to help players discover how to counter each pattern. The Wii remote vibrates to the beat, and Beats are always in rhythm, so it's only a matter of sticking with the rhythm to take them down with perfect timing.

At the end of each stage is a boss battle. Each consists of three waves of increasing difficulty and feature unique Beats not found anywhere else in the game. Since these battles take place at the end of each stage and are already difficult to reach, they tend to focus more on reflexes than pattern recognition, testing the player's skill. When times get tough at any point throughout a stage, a bomb can be detonated, destroying every Beat on screen. Players only receive one bomb per stage so it's important to make it last, and it's usually a smart idea to save it for the boss' unpredictable Beats.

Overall, the majority of your time spent with Core will be replaying the earlier sections of each stage, familiarizing yourself with each Beat and pattern. Memorizing each pattern and reaching the boss doesn't instantly guarantee mastery over a stage, though. Half the fun in Core comes from testing your memory and reflexes against waves of Beats in rapid succession. Nailing every Beat in the more complex sections can be very satisfying considering how difficult the stages are when first encountered.

There is a multiplayer aspect to Core, but it goes against the rhythm concept driving the entire series by having two players go through the same levels as the single player mode while firing beams from the same Core. The gameplay can only be partially salvaged by having each player agree to fire in only two designated quadrants of the screen, but that would leave you only experiencing half the game. It would have been interesting to feature two Cores and maybe a unique level for the multiplayer mode, but for a six dollar download, Core isn't ruined by having a lackluster multiplayer component.

Sights and sounds come together in gameplay to form one of the most unique rhythm games to date.

Obviously, Core's unique visuals and sound, "outdated" as they are, play a huge role in the game's appeal. By keeping majority of the Beats as simple, colored pixels, the player is quick to recognize their roles, and by having each level backed by a constant beat, players can fall into the rhythm while blasting Beats, which brings the sights and sounds of the game together in gameplay. The strange backgrounds can get in the way at times by flashing conflicting colors across the screen, but they only add to the challenge and style of the game.

Veterans of Bit.Trip Beat will be pleased to find that its sequel takes everything that made it unique and fun and makes it even better without feeling like the same old thing. Bit.Trip Core looks and sounds outdated, but it's a far more interesting and stylish evolution of the rhythm genre than the relentless guitar and karaoke sequels. If Core is any indication of how well developer Gaijin Games handles all of its sequels, it's comforting to know that there are four more Bit.Trip games in the works.