Xenogears is a 1998 Role-Playing-Game created by Square-Enix (then named Squaresoft). Following the success of Final Fantasy VII, Square was confident in building a game that had many conspiracies. Heavily detracted by crisis was the strong religious details interwoven in the story. Other negative reports focused on the father/son relationship main protagonist Fei Fong Wong had with his darker counterpart Grahf (reminiscent with the Luke Skywalker/Darth Vader relationship). The conspiracies and plot points were so heavily embellished that for a time Square considered not porting it over to North America.
Whatever the reason, Square did localize the game. The characters are unique and mature in interesting ways. Fei, for example, first shuns people in need because he's been poked and prodded by the villains. However in Kislev, Fei takes up the responsibility of saving as many citizens as he can from an airship attack. He inspires the confidence of others and often convinces many enemies to his side. The entire enourage of characters ultimately make for a endearing and tragic story.
The game's most unique concept is the "Deathblow" system and the use of giant mecha called "Gears."
Both combat systems share key similarities to offer a broader range to combat. The first device is the use of a "point" or AP System. The character can three different kinds of attack: light, medium, and heavy (Triangle, Square and X respectively) Each attack consumes "AP" or Ability Points: Triangle costs one point, Square costs two points, and X costs three. The AP is a the total pool of ability points from which the character can string combinations together. For example, a character with 4 AP can execute four Triangle attacks, two Triangle and one Square, two Squares and one Triangle, or one Triangle and one X. However, a 4-point pool cannot exceed combinations past 5 points. The AP pool grows at certain levels, allowing five, then six, and ultimately seven-point combinations. Certain combinations (always ending with a X attack) are called Deathblows, powerful attacks signature to the characters' fighting style.
The Deathblow system is tied to Gear combat. For every Deathblow learned, the mecha can execute a combination attack of its own. These combations are divided into levels of power from Level 1 to Level 3, with two attacks for each level. This forces the player to learn Deathblows for use in Gear combat, which is essential for overcoming enemy mecha in the game. The addition of a fuel system (each attack costs fuel, and Gears cannot function without it) forces the player to strategize his attacks. If the character has a maximum of Level 3 attack but low fuel, then the player can decide to to execute a weaker combination in order to conserve what fuel remaining.