NEC Avenue's caveman mascot for PC Engine. The headbutt attack, the rolling movement, and Hudson's rival mascot.
PC Genjin — Bonk's Adventure in the West — was developed by Red Company and published by NEC Avenue for PC Engine in September 1989 — a platform game featuring Bonk, a bald prehistoric boy who attacked enemies by headbutting them, created to serve as the PC Engine's mascot character against Sega's Alex Kidd and Nintendo's Mario. The headbutt attack — running and launching head-first into enemies — was the central mechanic. Bonk could also hang from ledges with his teeth and perform spinning attacks. PC Genjin sold approximately 800,000 copies and established Bonk as PC Engine's most recognizable character.
About this game
PC Genjin — Bonk's Adventure in North America — is the platformer that Hudson Soft built to be the PC Engine's answer to Super Mario Bros. Released in Japan in December 1989, it stars a large-headed prehistoric child named PC-Genjin who attacks enemies by headbutting them. The name is a double pun: PC stands for both "PC Engine" and "Pithecanthropus Computerus." Designed from the ground up as a mascot game for the console, it was vibrant, fast, and technically impressive — demonstrating what the PC Engine's graphics hardware could achieve at the beginning of the platform's library.
Key Features
A headbutt attack system in which the protagonist's large cranium is the primary weapon — used to stun enemies, bounce off walls, and interact with the environment. Smooth multi-directional scrolling that showed the PC Engine's technical advantage over the Famicom. Seven stages set in prehistoric environments, each concluding with a boss encounter. Three difficulty levels — Beginner, Normal, and Hard. A lives system with continues. The game was specifically designed to serve as a technology showcase for the PC Engine hardware at point-of-sale demonstrations.
Gallery
The Story Behind
By 1989, the PC Engine was two years old and had established itself as a genuine competitor to the Famicom in Japan. Hudson Soft had invested heavily in the platform — they had co-designed the hardware — and needed a mascot title that could anchor the console's identity the way Super Mario Bros. anchored Nintendo's. PC Genjin was the answer. The character had appeared in Gekkan PC-Engine magazine in comic form before the game launched, building brand awareness among the platform's audience. The game sold approximately 350,000 copies, establishing Bonk / PC Genjin as one of the defining characters of the PC Engine era. It was one of the first TurboGrafx-16 titles in North America, where NEC used it as a key launch window title for the console.
Tricks & Tales
The character's Japanese name — PC-Genjin — contains a pun that does not translate into English. "Genjin" (原人) means "prehistoric human / caveman," but it also sounds like "PC Engine" with the name restructured. The North American name "Bonk" refers to the headbutt attack. The European name "BC Kid" makes a different joke: "BC" means "Before Christ" — a prehistoric era joke. Red Company provided the original character design; the game development was led by Atlus with A.I. handling background art, all under Hudson Soft's supervision — a remarkably distributed development team for 1989.
Collector's Guide
Region & Compatibility
Japan: PC Genjin (PCエンジン). North America: Bonk's Adventure (TurboGrafx-16). Europe: BC Kid. All regional versions play on their respective hardware. The Japanese version is titled and described in Japanese. The TurboGrafx-16 version has minor regional differences but equivalent gameplay.
Maintenance Tips
PC Genjin is delivered on HuCard — a credit-card-sized ROM module with no moving parts and no internal battery. HuCards are among the most durable game media ever produced; the contacts may oxidise with age but respond well to gentle cleaning with isopropyl alcohol and a cotton swab. Do not flex the card. The contact strip is along the bottom edge. Avoid storing HuCards loose in drawers — use a case or the original box to prevent contact scratching.
Going deeper
Explore the machine this game ran on, and what to check before you buy or care for one:
What to Watch Out For
Before buying, these are the points worth knowing — from someone who handles original Japanese PC Genjin (Bonk's Adventure) copies regularly.
Will this Japanese PC Engine game work on a North American TurboGrafx-16?
Not without a hardware adapter. The TurboGrafx-16's data bus lines are wired in reverse compared to the PC Engine, making the two regions physically incompatible at the cartridge (HuCard) slot level. A passive adapter such as the dbElectronics Turbo PC-Henshin bridges this gap for HuCard titles. For CD-ROM² software, the TurboGrafx-CD drive will run Japanese discs if they do not carry a software region check, but compatibility varies by title. In both cases, Japanese PC Engine software is designed for the Japanese market and carries no English text.
How should I store and clean a PC Engine HuCard?
Keep HuCards in their original plastic sleeves or a protective case, away from humidity and direct sunlight — the exposed gold contacts oxidize over time. To clean: apply 90%+ isopropyl alcohol to a cotton swab and gently wipe the gold edge contacts. Never blow on them — breath moisture accelerates corrosion. Handle by the plastic edges only, avoiding the contact strip. HuCards have no internal battery and no moving parts, making them among the most durable formats from the era.
Does this HuCard have an internal save battery?
HuCards do not support internal battery backup by design. If this title requires save data between sessions, it either uses a password system or requires an external backup peripheral (such as the Tennokoe Bank or Backup Booster) connected to the PC Engine's expansion bus. Check the game manual for the save method — many action and strategy HuCard titles are designed as single-session experiences and do not require saving at all.
Before You Buy
Things worth knowing before you buy PC Genjin (Bonk's Adventure)
A short checklist for buying used PC Engine software wisely — useful with any seller, anywhere.
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Choose a seller who tests it before shipping
A copy that has actually been powered on and checked is a known quantity. An untested one is a gamble you only settle after it arrives.
Look for a seller who states it was function-tested and says what they confirmed. A serious seller can tell you exactly what was checked.
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Make sure it fits your console
Japanese PC Engine HuCards and CDs are not compatible with the North American TurboGrafx-16 — the formats differ. Use a Japanese PC Engine system.
Play it on a matching Japanese console or a region-free system, and confirm the listing states the region.
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HuCard or CD-ROM² — know which you're buying
PC Engine games come on HuCard chips or on CD-ROM². CD titles also require the right CD system and a working System Card.
Confirm the format in the listing, and for CDs check the disc surface and that saves are supported.
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Check that the contacts are clean
Dirty edge contacts are the most common cause of startup and sound trouble in cartridges of this age.
Choose a seller who cleans the contacts before shipping. A note that it was tested and cleaned means the basics were handled.
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Read the seller's reviews and return policy
A 100% positive record across thousands of sales is close to a guarantee — packing, communication and problem-solving all work for everyone. A return policy protects you if something is off.
Read the feedback and confirm a clear return window before you buy.
The last step before buying anywhere is knowing what it's worth.
See what it's selling for on eBay →Unexpected Discoveries
Games you weren't looking for — but might be glad you found.
Rooms this game lives in
Wander deeper — explore the themed rooms where PC Genjin (Bonk's Adventure) sits alongside its kin.
Memories from around the world
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