Lunar Knights, known in Japan as and abbreviated Boktai DS, is an action role-playing video game, the fourth title in the Boktai series of video games developed by Kojima Productions and announced at E3 2006. The game was revamped to remove the necessity of using the real-life solar sensor due to player troubles; however, it still retains the functionality if any of the Game Boy Advance Boktai cartridges are inserted. As some gameplay features are exclusive to Japan, the original names of the characters are used in such instances. Gameplay Lunar Knights revolves around two characters: Lucian and Aaron. Lucian is a vampire hunter, wielding various dark melee weapons. He is also imbued with the power of darkness, and can change into a vampire after he builds up a Trance (shortened to TRC in-game) meter by fusing with his Terrennial, Nero, which allows him to absorb life out of his foes. Aaron is an apprentice sharpshooter, and uses a variety of Solar Guns to deal damage to his undead foes. Unlike Lucian, Aaron has light powers, and can temporarily become an avatar of the sun when needed by fusing with his Terrennial, Toasty. The player increases the two characters' levels by killing enemies, and their weapons may be upgraded with various parts, allowing more abilities to be used with that weapon. The ultimate goal in Lunar Knights is to destroy a number of boss vampire enemies, in which the basic mission is to defeat each of them in their respective dungeons, either by exploiting their elemental weakness or using Trance. Once this is accomplished, the boss is launched into space using the Casket Rocket, Laplace; the player then enters a minigame consisting of three parts. The Casket Rocket is controlled from a third-person perspective with the stylus. By moving the stylus, Laplace moves, and tapping the screen causes it to fire lasers. After these three segments have ended, there is a short video segment in which the defeated boss is purified with the intense solar radiation in the stratosphere, made possible by the Interstellar Satellite Sunflower. As more bosses are defeated, the player is able to gain access to different elements through terrennials. There are four different terrennials available besides Nero (Dark) and Toasty (Sol): Ursula (Flame), Tove (Earth), Alexander (Cloud), and Ezra (Frost). With each acquired terrennial comes a different climate for the player to manipulate. This can be