'Boktai' is a series of Action-RPGs for the Nintendo Game Boy Advance System, produced by Hideo Kojima, creator of the Metal Gear series, and written and directed by Ikuya Nakamura.
The first game in the series, Boktai: The Sun is in Your Hand, was released in Japan on July 17, 2003 and in the US on September 16, 2003.
The game is unique in that its cartridge contains a solar sensor which allows the player to harness the power of real sunlight in combat and puzzles. It was praised by critics at the time for solid gameplay that backed up its unusual gimick.
In Japan, the game was called ボクらの太陽 (Bokura no Taiyō), literally Our Sun. Hence, Bok + Tai.
In Japan, the game was packaged with a UV-sensitive card that players could set in the sun to gauge the level of UV radiation on a given day.
Learn more by checking out the game's Wikipedia page(s), or by perusing the Links and Media pages.
How Can I Play It?
Unfortunately, Boktai has not been released on any modern hardware since its initial release. It is likely that the game's defining characteristic, its solar sensor, makes this difficult. Its very small following is another likely factor.
Play via emulators is made possible by fan-developed mod patches which allow for in-game control of the solar sensor.
Play on original hardware is possible through the use of a flash cart with the aforementioned solar sensor patches. There is also a flash cart with a built-in solar sensor, if you want to get really authentic (out of stock at time of writing).
Fan-made translation patches also make it possible to play Boktai 3 in English.
Note: Reproduction carts can be found for purchase online, but they are sold by independent vendors who tend not to credit or benefit those whose work has made solar sensor and translation patches possible. When seeking these games out, remember that they are kept alive by a small community of dedicated fans. Support their work where you can.
About the site
Use the four links at the top of each page to switch to the relevant information for the corresponding game. For example, clicking 'Boktai 2' at the top of the Music page will take you to the music page for Boktai 2. And so on.
This is a personal project that I'm working on in my free time, so it'll likely take a very long time before a significant amount of information is available. Thanks for your patience!