Joystiq has a review of one of the titles included on the Xbox 360 hard drive: Hexic HD. Unlike the other Live Arcade games you don’t need to spend any Microsoft points to get the full version as it is included 100% free from the start.
Hexic looks like your typical puzzle game from its shiny and brightly colored panels, but the way you play it is mainly by rotating trios of hexagons around central axes in a hexagonal grid to strategically remove clusters of tiles from the board. As the official Microsoft site for the game says, you must use “bonus pieces and starflowers to boost your score and discover new ways to play. But watch out for bombs-—clear them before they explode or it’s game over.”
In the end they give Hexic HD an 8/10, which is better than some of the largely published games are getting, so if you have a chance, run some Hexic HD, and have some real semi-retro fun.