If you appreciate the work done within the wiki, please consider supporting The Cutting Room Floor on Patreon. Thanks for all your support!

Osomatsu-kun Hachamecha Gekijou

From The Cutting Room Floor
Jump to navigation Jump to search

Title Screen

Osomatsu-kun Hachamecha Gekijou

Developer: Sega R&D2[1]
Publisher: Sega
Platform: Genesis
Released in JP: December 24, 1988[2]

SoundIcon.png This game has unused sounds.
DebugIcon.png This game has debugging material.

Osomatsu-kun Hachamecha Gekijou (roughly Little Osomatsu: Nonsense Theater) is a platform game based off the popular manga Osomatsu-kun. It was not only the fourth title for the Mega Drive (the Genesis wasn't even a thing yet), but also the system's first exclusive (Space Harrier II, Super Thunder Blade, and Altered Beast were all arcade ports).

Players take on the role of Osomatsu, adventuring through a surrealistic theater-themed world, trying to save his five brothers who have been kidnapped by a duo consisting of a Frenchman named Iyami and a short boy, Chibita. A otherwise ordinary platformer, its infamy is much, much bigger than the game itself - quite literally in this case.

The game is infamous among kusoge enthusiasts, as it had quite the storied history - over half of the game was cut out thanks to a chip shortage, and its poor quality was so offensive that Osomatsu-kun artist Fujio Akatsuka threw an ashtray at Sega's developers during a meeting. To say this game left a bad taste with Sega fans of the time would be a understatement - it practically set back the Mega Drive's brand in Japan!

Today, it is little more than a curiosity in Sega's history and symbolic of the problems with Sega's home consoles at the time. Prior to 2015, this game was the only media Fujio Akatsuka was known for in the West (in fact, the first few pre-Osomatsu-san videos on YouTube were of this game), but Osomatsu-san's sleeper hit status changed that in no time.

Since this game predates the TradeMark Security System, it rarely runs on anything other than a pre-VA6 Model 1 Mega Drive.

Leftover Debug Functionality

The game has some debug functionality left over, but the way to trigger it is not only disabled, but doesn't appear to work right. Before a new screen starts, activate the Pro Action Replay code 635E:4E71, then turn it off after the level begins.

Elementary, my dear Cactus.
This needs some investigation.
Discuss ideas and findings on the talk page.

Afterward, you have nearly free movement (Osomatsu-kun is still bound by level object collision). A and C cycle through Osomatsu-kun's sprites. Hitting Start on Controller 2 exits this mode with no obvious way to get back in.

(Source: andlabs)

Unused Jingles

Spread across the ROM (these were found when the .VGM rip by Project2612 was made) are various unused jingles. Most of these appear to be drafts for the game over jingle.

Track number: 8A

A slow variant of the game over jingle.

Track number: 8C

A louder variant of the game over jingle, this time with more instruments.

Track number: 8D

A faster variant of 8C.

Track number: 8E

A short jingle, which bears little resemblance to the others in the game.

Track number: 90

A short fanfare.


  1. It can be inferred that R&D2 was involved, thanks to R&D2 employee Yasushi Takeuchi listing the game in his interview for Saturn Fan.
  2. https://www.sega.jp/fb/segahard/md/soft.html