61 video games have been 'delisted' from Microsoft's Xbox Live Arcade service to date. Some, such as the recreations of pithy 80s arcade games like Defender, Robotron 2084, Double Dragon and Gauntlet are readily available to play in compendiums elsewhere or, if you've the budget, on their original cabinets. But others, such as Microsoft's experimental virtual game show 100 vs 1 or Sumo Digital's elegant tribute to arcade racing games OutRun Online Arcade or Double Fine Happy Action Theater (a game designed by Tim Schafer as a way for his two-year old daughter to interact with a TV screen) are no longer available to buy anywhere. These video games may be lost forever in the ebb of digital distribution's uncaring tide.Microsoft is evasive on the reasons behind the disappearances. Pressed on the issue a spokesperson provided the following tepid statement: "We work closely with our development partners to ensure that gamers have access to great titles through Xbox Live, which sometimes includes the removal of content due to expired rights and licensing or other circumstances specific to developer/publisher terms." Expired rights and licences limiting the sale of video games is nothing new - it's one of the reasons that we're yet to see a re-release of 1997's seminal, James Bond tie-in Goldeneye 007. But in the past, a licensed game would remain available to buy on the second hand market. In the digital age, there is no physical artefact. Once it's removed from sale, it's gone without trace.Indeed, while these 61 games remain on Microsoft's servers (anybody who previously bought one of these games and deleted it is currently still able to re-download the game), the moment those servers are shut down, a great swathe of video game history is wiped away. Where once we could place our treasured games and memories in cardboard boxes and store them in attics, increasingly video games are ephemeral things, fleeting and formless.
"It's a big problem already, and I suspect it's going to be even bigger 20 years from now when historians find themselves unable to experience significant works like World of Warcraft."
Frank Cifaldi
Sega's OutRun Arcade Online was removed from PSN on October 13, 2010 and Xbox Live Arcade in December 2011 after a licensing agreement with Ferrari expired.

Frank Cifaldi is a self-professed video game archivist and historian. He runs Lost Levels, a website dedicated to unreleased video games. But he also has a special interest in digital games that made it to market but are no longer available to buy. He works for the studio that made War of the Worlds, one of the disappeared titles on Xbox Live. "It's a big problem already, and I suspect it's going to be even bigger 20 years from now when historians find themselves unable to experience significant works like World of Warcraft," he tells me. "We're always going to be able to approximate the experience of viewing Birth of a Nation the way it was originally intended, but we don't have a solution for how to recreate games that require not only hundreds of active players, but the proprietary servers that may no longer exist."Some might argue that the deleted games hold little significance: primarily comprised of dated sports games and barely concealed adver-games. But for Cifaldi it's not just an issue of not being able to preserve games that are considered culturally significant today. "The maddening part about preserving video game history is that we just don't know what's going to be important 50 years from now," he says. "Art - especially risky, forward-thinking art like games - has a way of going unnoticed when it's contemporary and discovered years later. For all we know we're still in the silent movie age of what interactive media is evolves into. If we're not hanging on to every scrap of our history now, we're going to inevitably lose things that could benefit society in the future."Henry Lowood is curator for history of science & technology collections and film & media collections in the Stanford University Libraries, where he works to preserve and archive video games. He is optimistic about the work being done to save our games. "In terms of the technical means for preserving software, cultural repositories such as museums, libraries and archives are making great progress." Stanford University Libraries acquired its first major historical collection of software more than 15 years ago. "Since that time, we have been working on a variety of problems related to software preservation such as cataloging, data migration and access," he says. "We have developed a digital repository capable of storing and preserving software and many other forms of digital information and artifacts."But there are many problems unique to preserving contemporary digital video games in libraries such as Stanford's. Online activations, authentications and online gameplay modes that require active servers in order to work make storing working copies of games almost impossible in some cases. Then, of course, there's the problem of obtaining code for video games that only exist in digital form. "When access to digital-only software is cut-off the likelihood that particular software title will be lost permanently increases," says Lowood. His work at Stanford involves attempting to convince publishers and rights-holders to discuss possible ways of archiving their games. Unfortunately, while a few publishers willing to engage in conversations about how to preserve games, Lowood states: "Many are not".