When the man who created Tetris comes up with a new idea, it's worth hearing. When that idea turns out to be a puzzle game that rivals his claim to fame, well, that's worth even more. Ironic, then, that the incredibly valuable Hexic HD is yours free.

The game that came preloaded on your Xbox 360 hard drive as a thank-you from Microsoft looks simple enough: a field of multicolored, jewel-toned hexagons, each rotatable with two of its neighbors. Shuffle them around until three colors match, and poof, all three disappear. But the more you play, the more Hexic reveals and rewards. Soon you're creating more complicated shapes, defusing game-threatening bombs, wiping out entire swathes of jewels in one clever combo, incorporating new colors of hexagons and earning special pieces like silver stars and black pearls. With those special pieces come novel ways of rotating the other jewels they border, and suddenly high-scoring opportunities - including ones for disaster - lurk everywhere on the board. It sure looked easy at the start.