In Aqua, the player commands an elite cruiser to navigate a world filled with vast seas and scattered isles. The game world is seen from a bird eye perspective with the camera tightly following the player's ship, with the exception of cinematic sequences. The player moves their ship with the left analogue stick and fire their primary guns with the right stick. Primary guns incorporate rapid firing machine guns, slower firing cannons, flamers, or other specialized guns. Also at their disposal are mines that can be used as both offensive and defensive tools. The player can lay whole mine fields to their liking, creating traps and strongpoints. Several types of torpedoes are another way of quickly disposing of intrusive enemy vessels. To compensate for being often vastly outnumberd in battles, the player can also employ AI controlled squads of elite watercrafts, giving them various context orders to influence the outcome of battles. And for situations seemingly lost, there is a special weapon, extremely powerful and devastating, that can be called in every time the player collects enough energy called Aquaflux that drops from destroyed enemies.
Source: Wikipedia, "Aqua (video game)", available under the CC-BY-SA License.