to the overall content of the game. Eight new commanding officers join the original game's eleven to make a total of nineteen. Many new maps were added for Versus mode and War Room, although most of the new maps and commanding officers are not available for use at the start of the game, and must be purchased from the in-game shop after certain conditions are met. Only one new unit, the Neotank, was added to the original set in Advance Wars. Two new terrain features were introduced: the Missile Silo and the Pipeline (along with its breakable Pipe Seams). The Missile Silo can be fired by foot troops to deal area of effect damage, and pipelines act as impassable walls. Because of its function as a wall, players can use it to create maps smaller than the default dimension the map editor provides, something that was not possible in the game's predecessor. Along with the two terrain features, various new special Black Hole buildings were also introduced in Black Hole Rising, although they are only found in the game's campaign. These properties directly affected the gameplay of missions they are found in, creating new objectives for the player such as destroying or capturing one of these special buildings. An example of such a building is the large Black Cannon, which fires on one non-Black Hole unit each turn, dealing damage to it. Destructible properties such as the Black Cannon have "health", represented by a heart icon. When units attack the property, the number decreases; when it reaches zero, the property is destroyed. One of the key added features of Black Hole Rising over its predecessor is the Super CO Power. The CO Power, introduced in Advance Wars, was a special ability unique to each commanding officer that could be triggered as the commanding officer's CO Meter filled by battle. CO Powers affected the game either by providing benefits for allied units and/or by inflicting negative effects on the enemy's units. Black Hole Rising changed the format of the CO Meter to use small and large stars, although it essentially still functions as a fillable meter. A regular CO Power is still available by filling the small stars, but a more powerful Super CO Power, introduced in Black Hole Rising, can be triggered by filling the large stars as well. Although a Super CO Power is in many cases better than