A mouse policeman outnumbered by cats. A mansion full of stolen goods. Against all expectations, a good time.
Mappy arrived in arcades in January 1983. The setup was a deliberate absurdity: a mouse police officer must recover stolen goods from the mansion of Goro, a large cat crime boss, while avoiding his cat subordinates called Meowkies. Because Mappy cannot fight, he navigates by bouncing on trampolines between floors and opening doors to stun enemies with bells, microwaves, and traps. The physics are specific — the double-bounce on a recently used trampoline sends him higher than expected — and mastering them is the game's quiet pleasure. The game's secret weapon was its music. Composed by Yuriko Keino, the Mappy theme is a jaunty march that matched the game's cheerful premise exactly — light, rhythmic, and impossible to forget. In an arcade environment of alien invasions and fictional wars, Mappy was domestically comic: a mouse, a cat, a mansion, some stolen pianos. The Famicom port, released in November 1984, was one of Namco's early translations of its arcade hits to the home platform. The character who resulted — round-headed, blue-uniformed, cheerfully outnumbered — has appeared in Namco compilations and anniversary releases for four decades, carrying the same gentle absurdity into every platform he has visited.
— inspired by Yuriko Keino
About this game
Mappy is a 1984 Famicom platform game in which the player controls Mappy, a mouse police officer who must recover stolen goods from a mansion run by a cat crime boss named Goro. Mappy cannot fight — he navigates by bouncing on trampolines between floors, opening doors to stun Goro's cat subordinates (the Meowkies) with bells, microwaves, and other traps. The game is built around precise timing, floor routing, and the specific physics of Mappy's trampoline movement. Its music — a jaunty march composed for the original arcade — became one of the most recognized pieces of Japanese game music of the 1980s.
The Story Behind
Mappy's arcade debut in January 1983 placed it in the same moment as Namco's other early-80s arcade landmarks: Galaga, Dig Dug, and Xevious had all arrived within two years. But Mappy was distinctive in tone. Where Galaga involved alien invasion and Xevious a fictional war, Mappy's world was domestic, comic, and deliberately un-serious: a mouse policeman, a cat crime boss with an aristocratic name, a mansion full of television sets and pianos. The character design embedded a visual pun: the cat crime boss is named Nyamco (ニャームコ), which inverts the syllables of Namco while adding the Japanese cat sound 'nya' (にゃ). This kind of self-referential playfulness was characteristic of Namco's early-80s game design — a willingness to be lighthearted in an arcade environment that was otherwise dominated by combat and survival. The Famicom port, released in November 1984, was one of Namco's early home translations of its arcade catalogue. Nintendo musician Koji Kondo later cited the Japanese arcade music of this period, including the Mappy theme, as a formative influence on the approach to game music he developed for Super Mario Bros. The Mappy character has appeared in Namco game compilations and anniversary releases for forty years, maintaining the gentle absurdity of the original through every platform he has visited.
Tricks & Tales
Mappy's trampoline physics have a hidden mechanic that separates casual players from experienced ones: if Mappy lands on a trampoline that is already bouncing (recently used), he bounces significantly higher than normal, allowing him to skip floors and avoid enemies in ways that look almost accidental. Mastering the double-bounce is the difference between barely surviving and moving efficiently through the mansion. The arcade version of Mappy was co-published in North America by Bally-Midway, but no home version was ever released for the NES in North America — the Famicom version remained Japan-only. The game's name 'Mappy' is derived from 'micro-police' — a small officer for a small criminal empire.
Collector's Guide
Region & Compatibility
The Famicom version was released only in Japan. The arcade original was distributed in North America through Bally-Midway, but no NES home version was ever produced for the North American market. All physical copies of the Famicom game are Japanese.
Maintenance Tips
The gold-plated edge connectors on Famicom and NES cartridges pick up skin oils and oxidation over decades — a gentle wipe with a cotton swab dampened in 90% or higher isopropyl alcohol, stroking along the length of the pins rather than across them, is the accepted standard. Let the alcohol fully evaporate before reinserting. The old habit of blowing into a cartridge is folklore: the moisture in breath causes slow corrosion of the contacts over time, and any improvement you felt came from the act of re-seating the cart, not from the breath itself. Nintendo eventually updated its own troubleshooting guidance to say explicitly: do not blow into your Game Paks.
Going deeper
More on keeping a Family Computer (Famicom) / NES alive, and what to check before you buy one:
What to Watch Out For
Before buying, these are the points worth knowing — from someone who handles original Japanese Mappy copies regularly.
Will this Japanese Famicom cartridge work on a North American NES?
No, not without an adapter. The Famicom uses a 60-pin edge connector; the NES uses a 72-pin connector with a different physical form. Third-party pin adapters allow Famicom cartridges to run on a NES. Alternatively, a Japanese Famicom or compatible clone console will play the cartridge directly without modification.
Is there a NES version of Mappy I should look for instead?
No. Mappy was never officially released for the NES in North America or Europe. The only licensed home versions of the game are the Japanese Famicom cartridge and ports for other platforms (PC-8801, MSX, etc.) that were also Japan-only. If you want the home console version of Mappy, the Japanese Famicom cartridge is the primary option.
Before You Buy
Things worth knowing before you buy Mappy
A short checklist for buying a used Famicom cartridge wisely — useful with any seller, anywhere.
-
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.
-
Make sure it fits your console
This is a Japanese Famicom cartridge with a 60-pin connector; a North American NES uses a 72-pin slot, so it will not fit directly.
Play it on a matching Japanese console or a region-free system, and confirm the listing states the region.
-
If this title saves your progress, check the battery
Cartridges that save use a small coin-cell battery that fades over decades — a dead one wipes your save without warning.
Ask the seller whether the save function was tested. Replacing the battery is possible, but doing so erases any existing save.
-
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.
-
Confirm it is genuine, not a reproduction
Sought-after titles are targets for reproduction boards with replacement labels.
Ask for a photo of the circuit board and look for factory markings. Favour a shop with a licensed second-hand dealer permit (古物商) — by law its stock has a traceable origin, your simplest guard against fakes.
-
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.
Memories from around the world
This is a young museum, and this page is still waiting for its first voices. The memories people send reach Taisei personally, and the ones that move him find a home here over time — always with the writer's blessing. Yours could be the very first for this game.
Share your memory ↑