What makes a game - any kind of game - great? Part of the fun is derived from the rules. The order that they bring to the chaos of possibilities is both a road-map to victory, and a puzzle that can thwart even all but the most attentive players. The truly great games like poker add an element of chance. Nobody knows what hands will be dealt, and a great player can lose to a beginner if the cards fall right. Even games like chess, which begin identically, mix things up by relying on some players to see "deeper" into the game, and others to make errors.
Advance Wars 2: Black Hole Rising is that type of game. It's a simple turn-based battle game for the Game Boy Advance system, and at first it doesn't look like much. Players move military units like squads of troops, tanks, or aircraft carriers over a grid-based landscape, in an attempt to defeat their enemies. The structure is chess-like in its simplicity, with each unit given a special ability and advantage. But imagine chess played on a board where terrain made a difference - a playing field sliced-through by rivers and peppered with protective forests. A well-placed basic unit can destroy the mightiest force in a game like this, and that's what makes Black Hole Rising so compelling.
What makes it challenging is the inability of all but the strongest players to understand the intricacy of such a simple system and plan accordingly. Battles may be won or lost based on unit strength and terrain, but the war is won by good players making fewer errors than their opponents.
There are plenty of other pleasures to be found along the way. Armies are commanded by generals with special abilities that can turn the tides of a battle. Players can design their own maps and battle on them with friends. There's even something resembling a story. And all of this is contained in a hand-held piece of electronics. But the greatest source of Advance Wars 2 's strength as a game is its solid rules system, which is balanced to an astonishing degree. It lets players derive as much pleasure from the way that the game is played as they do from the various battles themselves.