Lunar Knights, a sequel to Konami and Kojima Production's Boktai series in a spiritual sense, foregoes having to harness the power of the sun in exchange for good old fashioned video game adventuring, Instead of forcing players to rely on the mercy of real-time weather, it gives them the option to control the climate themselves. (However, hardcore fans can still go outside and use the system's sun sensor). Game play changes of this caliber make Knights a more compelling experience.

In Knights, players control two special characters -- Aaron and Lucian (players can change their names to something more personal). Lucian sports a Goth-like appearance and wields a legendary blade called the Dark Sword. Aaron belongs to a group of renowned vampire hunters (not the Belmonts), destined to make the world safe again. They form an uneasy alliance when a vampiric guild called the Dark Tribe covers the world in darkness with the paraSOL system. The pair not only has to eradicate the Dark Tribe and its army of monsters, but return the world to its former bright self.

Aaron uses a run-and-gun shooting style, while Lucian swings his Dark Sword to chop enemies. Like Castlevania: Portrait of Ruin, players switch off between the two characters at any time. Power-ups can also be acquired over the course of the adventure simply by paying a visit to a friendly scientist.

This sounds typical for an action/RPG, but three aspects help Knights stand out. First, both Lucian and Aaron summon Terrenials to enhance their attacks. These elemental items can be activated at any time in the sub-menu. They combine with weapons and armor to give them greater power. The two characters also merge with a Terrenial by building up an emotional meter over the course of the game, giving them a superior but temporary attack. The characters then recharge their energy, with Lucian preferring moonlight and Aaron regaining power in the sun.

That leads to the second big feature -- the controllable climate system. Players alter this system upon visiting the old scientist, which helps in a number of ways. Certain weapons and items work better in particular climates. These changes affect the level itself and the enemies within it.