Xbox Live Arcade's casual gamer theme screams, 'puzzle games'. Though there are a handful of decent puzzlers out there almost two years into the 360's launch, none really matches up to this Street Fighter offshoot.
The gem-based puzzle game is about as basic as they come, though the rules and setup vary quite a bit depending on which mode you are playing. Modes X' and X are virtual twins, with X' being the 'remix' the title mentions; offering a rebalanced take on the original X mode, adjusting the drop patterns for some of the more powerful characters for parity. Both modes play by the same rules, where gamers get two-gem sets to maneuver and drop onto the bottom of their board.

Gems of the same color can combine into mega gems, beginning with four gems in a square pattern. The mega gems can grow in size with additional equal length same-colored-gem drops, and wreck extra havoc on the other player's board when cleared. Gems are cleared with same colored 'crash' gems, round instead of square, that eliminate all adjacent gems of the same color when they land. Clearing gems causes an 'attack' on the other player's board, in the form of 'counter' gems. Each time the player places another set of gems, the counter (which begins at 5) decreases by one. If it reaches zero, the gem transforms into a regular colored gem. The only way to clear a 'counter' gem is to clear blocks next to it, making them quite the nuisance.
If the addictive X modes are not enough for you, the game offers up two completely different gameplay options with Y and Z. In Y mode, gamers will actually start the game with a handful of 'counter' gems on their screen, and changes the rules regarding how gems disappear. This mode uses a more Columns-like system, where three gems in a row, horizontally or vertically, will clear out on their own. There are no mega-gems to create for point-stockpiling or massive attacks on the other player. Rather, clearing blocks slowly increases your 'Super' meter located above your character's head. When full, a quick flick of the right bumper will ensure that your next 'attack' is a bit larger than a normal one. This mode takes a bit longer to play a single round, but is no less enjoyable.

Z mode actually changes the game the most, eliminating the gem drops altogether. Rather, the game begins with the board half-full of a smattering of regular and crash gems. Gamers must use a ghost-square to select and cycle the gems into mega gems, and clear the board with 'crash' gems. The entire time the board is (slowly, at first) pushing upwards towards the top, making quick, smart decisions and use of strategy a must. All four modes boast a campaign where you battle through computer enemies to victory, in one of four difficulty modes for each. The vast array of modes and difficulties would already make this game worth your 800 MS Points.