Physical, Forever: Boktai’s Advanced Cartridge Turned Sunlight Into Gameplay

Physical, Forever: Boktai’s Advanced Cartridge Turned Sunlight Into Gameplay

Bane of the basement dweller.

We should talk about Boktai.

If we’re going to celebrate the miracles and majesty of physical media here—and why wouldn’t we?—we can’t not talk about Boktai, the game that perhaps embodies the unique potential of physical media better than any other.

Boktai is one of those rare games that started with a mind-blowingly good elevator pitch and somehow turned out even better than that high-level concept would suggest. The elevator pitch? “What if Metal Gear were Castlevania?” And make no mistake, the Metal Gear name-drop there is hardly spurious. Boktai was produced by the guy who created Metal Gear, Hideo Kojima, and it really does play like he dropped a healthy dollop of Castlevania into his usual design framework. You sneak around, perform stealth kills, manage your visibility and the level of sound your actions generate, and try to take down (and stake down) the undead.

Boktai follows the last of a line of vampire hunters in their effort to take down the nefarious Count—very Belmont-coded. The protagonist’s father numbers among the Count’s victims, so there’s a personal element to his quest. But this Count has made it a lot further in his conquest of the living than Castlevania’s Dracula ever dreamed; by the time Boktai begins, the entire world has fallen under the vampire’s dominion and is perpetually shrouded by gloom. Maybe that’s because protagonist Django doesn’t wield an enchanted all-purpose whip with which to battle evil but rather relies on a solar-powered pistol, the Gun Del Sol. Although the Gun Del Sol offers impressive customization options and allows you to take down the undead from the safety of ranged combat, the solar-powered element is a bit of a vulnerability: battling bad guys at night requires careful resource management, because the Gun Del Sol’s power drains rapidly and you have limited options for recharging it after dark.

And in Boktai, “after dark” is quite a literal turn of phrase. Like a lot of cartridges of its era (2003), Boktai contained a battery inside its cartridge that powered a real-time clock. That is, of course, a feature unique to cartridges (good luck cramming a battery into a Blu-ray disc), but nothing that can’t be replicated for a digital copy of Boktai on any system with a system clock... which is approximately every computer and console since Dreamcast. That’s not what makes Boktai special.

Still, the real-time clock does play a huge part in the game! Boktai doesn’t just track time of day on an accurate 24-hour clock; it also keeps tabs on the date, as well as your approximate geolocation. The idea behind such an unusually granular real-time tracking system is that it allows the in-game time-of-day cycles to correspond to your real-world surroundings with utmost accuracy. Had Boktai shipped a couple of years later for a system with internet connectivity, like DS or PSP, it undoubtedly would have connected to a local weather service at launch in order to pull data on current weather conditions.

As day shifts into night and vice versa, the game world within Boktai transforms. Again, it’s a lot like the day/night cycle in Castlevania II, where enemies have the advantage of strength and numbers at night, while players have the upper hand during daylight hours. But where Castlevania II’s diurnal cycle lasts for just a few minutes, Boktai’s lasts, well, 24 hours, with sunset and sunrise on-screen syncing up with the ones in the world around players.

This was a novel if not entirely unheard-of feature in games at the time. MMOs already existed, for one thing, and the Nintendo fans likely to have been aware of Boktai had very likely dabbled in Animal Crossing for GameCube already: a game built entirely around circadian rhythms.

And that’s where the physical nature of Boktai comes into play. Konami shipped the game in a slightly oversized transparent Game Boy Advance cartridge. Now, admittedly, see-through plastics were all the rage in those days, including the Glacier color option for the original Game Boy. And of course Game Boy Color carts shipped in clear plastic as their standard design. In Boktai’s case, though, the clear plastic had more than just aesthetic value.

See, the Boktai cartridge contained more special hardware than just the save battery and real-time clock. It also included a truly unique element: a solar sensor. The cartridge could detect sunlight, and the game reacted accordingly. If you played the game outdoors in daylight, the Gun Del Sol would charge quickly and easily. Play in the dark and you had to rely on scarce, in-game recharge opportunities in order to restore weapon power.

This made perfect sense in a game where you found yourself battling vampires in order to push back against the threat of eternal night! There’s no such thing as a garlic sensor, and Nintendo would have claimed that as a Wario Land exclusive gimmick if there were. And a cartridge you soak in holy water would have been a disaster. So, instead, Konami focused on the vampire’s other traditional weakness and made Boktai a game ideally played in the sun.

There was a practical element to this as well. Nintendo didn’t build a backlight into the original Game Boy Advance hardware, and the system’s screen was notoriously difficult to see in anything less than daylight conditions. Nintendo did address this shortcoming with the side-lit Game Boy Advance SP, but Boktai approached this quirk of the system as a game design problem. Why not make a game that rewards players for minimizing their eyestrain? And, hey, why make it about vampires while they’re at it? Those guys hate sunlight.

The result? One of the most unique cartridges of all time... and one of the hardest to replicate. The solar sensor is not some superfluous side gimmick in Boktai; it plays into the central game mechanics and acts as a foundation of the game experience. Somewhat controversially, in fact! Folks with day jobs had a tough time playing Boktai, since the sun had usually set by the time they got home to play. People who live in northern climes, like Alaska and Greenland, have incredibly limited windows throughout the year in which they even have access to sufficient sun to make Boktai worthwhile. And even in Boktai’s home region of Japan, players generally need to start their day with Boktai, even in the summer, since the country’s abstention from Daylight Savings Time leads to upsettingly early sunrises and startlingly early sunsets.

Of course, there are ways to game the system. A proper blacklight provides the correct form of radiation to satisfy the cartridge sensor. And there are ROM hacks and emulators that allow players to set the sensor reading to “sunlight on”—though this has its limitations, too, since keeping the cart in direct sunlight for too long will cause the Gun Del Sol to overhead. But these cheats feel like, well, cheats. Half the fun of Boktai is trying to work out the best way to tackle the game, arranging your attempts to delve into a dungeon and drag a boss’ coffin to be destroyed by the light-activated Solar Pile device around your daily schedule... and the sun’s daily schedule, too.

Boktai would be possible to play as a tweaked digital release. But the Boktai experience would be radically different in any form besides the weird little cartridge that Konami shipped it in. Only a handful of games throughout the history of the medium have made such interesting thematic use of a built-in hardware feature, and are so inextricably tied to the cartridge they shipped in.