A quirky little set of Vampire-hutning games for the Gameboy Advance created by Hideo Koijma, which used a solar sensor built into the cartridge to detect sunlight. Using a magic gun called the Gun del Sol, you fought the hordes of the undead to try and rescue your mother, avenge your father, and bring the light of the sun back to the world. The series consisted of three Gameboy Advance games (the third of which never made it outside of Japan), and a DS "spin-off" of sorts called Lunar Knights that was set far into the future of the same canon. In Japan, the game was called Boktai DS. If you've played these games or think they sound interesting, this is the place to jbber about it!