Even with the minor arcade resurgence going on these days, the prolonged decline of the American arcade means that there's a whole generation of people who have had little opportunity to play any of the thousands of coin-operated games in their native cabinets. Even those who remember the ‘70s and ‘80s golden age of arcades probably only had the opportunity to sample a relative handful of games that were available at their local haunts.

For people who want to preserve this disappearing bit of gaming history, or experience cabinets they never had access to, Multiple Arcade Machine Emulator (MAME) is a godsend. It is one of the most ambitious emulation projects ever, encompassing tens of thousands of games with highly varied hardware, programming, and controls. Legal issues aside, MAME ensures that future generations will at least be able to play and study these games without having to track down an aging cabinet or circuit board.

But as comprehensive as MAME is, there are a number of arcade games that remain unplayable (or functionally unplayable) without access to the original arcade hardware. That fact came into stark relief this week with the news that developer Mitchell Corporation was finally selling the rights to its back catalog. That back-catalog includes obscure 2002 shooter game Gamshara, which has never been successfully emulated or ported to a home console, meaning few people have ever played it.

It turns out there are hundreds of these unemulated games floating around out there, as ably documented by sites like unMAMEd and System 16. For some of these unemulated games, the the MAME community simply hasn't gotten around to coding specific emulation support, or has found emulation too difficult. For others, there's no known digital ROM dump of the original hardware, usually because that hardware is only available in a few extant prototype boards floating around. Then there's a third category of games that can technically be emulated by MAME or other emulators, but which can't be truly experienced without the highly specialized controllers or display hardware built in to the original cabinets.

We did some research on games that fall into all three of these categories and came up with a list of 11 intriguing arcade rarities that you’d have to leave the house and search for to play. In an age where it seems every form of entertainment has been digitized and made available for download on the Internet, these remain some of gaming’s rarest experiences.

Computer Space

The very first coin-operated arcade game, released months before Pong in 1971, remains surprisingly unemulated to this day. That's partly because Computer Space ran on hard-wired integrated circuits—like many arcade games of the '70s—and not on modern microprocessor ROMs (controversial 1976 game Death Race is in a similar boat, and also remains unemulated).

While MAME ignores most of these pre-microchip games, the DICE project (Discrete Integrated Circuit Emulator) provides accurate recreations of early classics like Pong and Breakout through emulation. But DICE still hasn’t been able to crack Computer Space, because of its complicated hardware configuration. As a commenter wrote on the project's Work In Progress blog, "DICE currently only emulates single board games. A lot more code is required before DICE can handle games that use multiple boards including Computer Space or a board rack setup such as Indy 800. It might be a while before multiple board hardware games are emulated."

If you want to experience Computer Space without tracking down one of its distinctive glittery cabinets, your best bet is to try out one of a number of simulations, coded from scratch to be as close as possible to the arcade game (or to Spacewar, the original PDP-1 game that served as its inspiration).

Crazy Otto

Of all the Pac-Man hacks out there, many of which are emulated on MAME, Crazy Otto is doubtlessly the most important. The game started out as a conversion kit for the original Pac-Man made by General Computer Corporation (GCC), which added new mazes, faster gameplay, and a funny-looking “Pac-Man-with-legs" main character. Production of Crazy Otto was stopped rather quickly after it started, though, as the result of a related lawsuit with Atari. Rather than give up, GCC took their game to American Pac-Man distributor Midway, who liked it so much that they bought the rights and converted it into a little game now known as Ms. Pac-Man.

While there are still a few rare test-location prototypes of Crazy Otto out in the wild, the ROM file has never been dumped for emulation purposes. GCC reportedly considered releasing the game's ROM back in 2010, that promise never came to pass. For now, your best chance to play this historical rarity is by hoping to find it at a show like California Extreme or PAX.

Cutey Fatty

There are some games we're kind of glad have never gotten the MAME treatment, and this obscure 2002 title by Korean outfit Wecom is one of them. A post on Arcade-History.com summarizes the ridiculous premise:

A girl named Cutey Fatty weighs over 100kg but she really wants to be a super model. So she has to lose weight fighting her favourite foods around the town. Her enemies are hamburgers, chocolate cookies and ice creams and so on. She should defeat the enemies and lose weights with getting vegetables and fruits in every stage. While the game playing, the scale is indicating her real time weights and she can lose weight more easily with intensive exercises if she finds secret door. And Toto her pretty dog helps to defeat the enemies.

With a concept like that, perhaps its better that the cabinet never seems to have made it out of Korea, or into any PC or console ports (though a version was reportedly planned for the obscure GamePark 32 handheld). If you really want to play a game like this, the premise behind Konami's Famicom title Yume Penguin Monogatari is similarly ridiculous.

Marble Madness 2: Marble Man

Anyone who's had the pleasure of playing the original Marble Madness on a trackball equipped arcade cabinet knows it's one of gaming’s truly unique classics. After the original game's 1984 release, and many subsequent home ports, a declining Atari Games finally got around to creating a sequel in 1991, adding more levels, new enemies, new obstacles, and support for a third player. A handful of prototypes got as far as location tests, but underperformed next to the slick Street Fighter clones that were popular at the time. Atari eventually scrapped the Marble Man project so to work on its own fighting game, Guardians of the Hood.

In the decades since, collectors have gone to great lengths to track down the prototype boards and cabinets for the game. Still, the game is so rare that not one of the 7,617 members of the Video Arcade Preservation Society has it listed in their collection. And though the prototypes do sometimes make an appearance at shows like California Extreme, the ROM has yet to be dumped.