Game concept: tile matching game. screen is populated with random tiles, each having a pair. when two matching tiles are selected, they are removed from play, revealing more tiles underneath. when all tiles are removed, the game is won. tiles hidden from view and under other tiles are inaccessible, which means that the game is not always solveable.
Controls: use d-pad left, right, up, down, to toggle through all available tiles. active tiles should either glow via a color filter or magnify slightly. select a tile by pressing the center of the dpad. use d-pad left, right, up, down to toggle through remaining visible tiles. select the pair by pressing the center. use back arrow to unselect a tile. game pause could bring up a screen prompting to restart, resume, or exit. alternately, clicking the back arrow when a tile is not selected could bring up a screen prompting to restart resume, or exit. (Controls are identical to solitaire, which has already been successfully ported for Zune.)
other game names: Mahjong, Mahjongg, Mah Jong, Taipei, tile solitaire. A version originally shipped as "Taipei" bundled in the game pack with Win98, tiles were hexagonal. There is supposed to be an open source 2D XNA version which was ported as a demo for Xbox. There is a pocket PC and mobile version. Ipod also has a version with screenshot and description
here.