Bust-A-Move's brand of bubble-shooting gets ported from platform to platform almost by default, seemingly immune to innovation. The PSP version shakes some cobwebs loose, adding some new tricks and a haunted-house theme that contrasts with the ever-present blank-stared cuteness of the twelve cartoon characters.

For those who've never played a Bust-A-Move before, the concept is simple: Aim a crossbow to launch colored bubbles into a playing field that's full of them, matching up three or more to pop them and clear the field. Special bubbles bowl a path through the crowd, blow up neighbors or erase particular colors from the board entirely. The whole shebang is colorful as hell, and eschews fashionable 3D graphics in favor of sharp old-school sprites. Lining up shots is simple, but requires true geometric skill to nail the best popping opportunities. Oddly, the analog stick does nothing, the manual's protestations to the contrary notwithstanding.

Deluxe throws in four exclusive new modes for bubble-popping veterans: Running Launcher oscillates the platform back and forth; Mix 'Em Up constantly changes the color of bubbles on the field; Shot forces you to clear a board using one well-placed snipe; and Time Warp unpredictably (and nauseatingly) varies play speed. All could've easily been vapid gimmicks, but instead prove interesting variations, requiring unique strategic tweaks. These are in addition to the familiar 300-puzzle classic mode, a challenging Ghost variation that renders bubbles insubstantial until bounced off a wall, See-Saw balance puzzles and Blind fields that only reveal colors of bubbles you've bumped.