Phalanx, a 2D side-scrolling shooter originally released in 1992 for the SNES, comes to the Game Boy Advance with you in the role of Rick Sanada, the only pilot capable of flying the A-144 fighter. Dispatched to the distant planet of Delia IV to investigate the disappearance of a research team, you become embroiled in a do-or-die conflict with an alien armada. While traversing the planet's core, an asteroid belt, deep space, and more (a total of eight levels), you utilize power-ups, such as homing and explosive missiles, energy beams, and super bombs. Other power-ups increase the damage potential of your ship's weapons and provide extra shielding.<br><br>Weapons, stored in four compartments selected via the R button, can be changed "on-the-fly" to deal with each situation. If your ship is destroyed, only the currently selected weapon is lost. Specific levels alter the standard horizontal-scrolling formula, by requiring maneuvers in strong water currents, or attacks against the exterior of a massive alien vessel before fighting your way inside. Sub-bosses populate the many levels, some of which are home to three or more of the screen-sized monstrosities.