With advancing console generations and the slow demise of both backward compatibility and digital game storefronts, the ability to play older games has always been tough. Through a new study from the Video Game History Foundation (VGHF) and the Software Preservation Network, we now have a better understanding of just how difficult accessing older games really is.

“87% of classic video games released in the United States are critically endangered,” wrote Kelsey Lewin, co-director of the Video Game History Foundation.

You can read the full report here, and the Video Game History Foundation also wrote accompanying summary blogs with highlights from the report.

The report defines “classic games” as (and if you’re of a certain age, you may wanna sit down for this) a game that was released before 2010.

“We identified the 2010s as the beginning of an era when digital distribution for retail-scale video games became viable and widely adopted on home video game consoles,” the report read.

Confirming the release status of every video game published before 2010 would have been an impossible undertaking, so the report focuses on a sampling of 4,000 games released in the US on one of three consoles that have been chosen to represent different levels of community and commercial interest. Here’s how the VGHF defined those categories:

Abandoned ecosystems, with low commercial interest and few games available. For our example, we picked the Commodore 64.

Neglected ecosystems, where there’s a lot of commercial interest but still not many games in print. We picked the Game Boy family, from the original Game Boy through the Game Boy Advance.

Active ecosystems, where games for these platforms are being re-released all the time. We picked the PlayStation 2.

The study found that, across all three categories, the number of games available never reached above 20 percent, meaning around 80 percent of games published before 2010 are not accessible.

The VGHF called out the Game Boy specifically, with only 25 games out of the 1,873 total games released during its lifetime still available for purchase. That number used to be significantly higher — 155 games higher — before Nintendo shut down the 3DS and Wii U virtual storefronts back in March of this year.

“When the eShops were shut down, the majority of all Game Boy games on the market fell out of release,” wrote Phil Salvador, library director for the Video Game History Foundation.

This report was an attempt to provide a scholastic explanation for something gamers already intrinsically know: it is hard to play old games, it is only getting harder, and if something more substantial is not done to preserve and make more widely accessible what little we have left, we will lose video game history.

“Video game history is more than just the bestsellers,” Salvador wrote. “If we want to understand and appreciate the history of video games, we need more than a curated list of the games that publishers decide have commercial value.”

Libraries and other archival institutions should be able to step in for those classic games that don’t generate the same kind of interest an old Mario or Sonic game might. But they have been increasingly hampered by strict copyright restrictions, notably the Digital Millennium Copyright Act, or DMCA.

“The cultural heritage sector has petitioned the U.S. Copyright Office for greater exemptions to the Digital Millennium Copyright Act to allow libraries and archives to expand preservation- and access-related activities for video games,” the report read.

However, the Entertainment Software Association, or ESA, the lobbying arm of the video game industry, has opposed DMCA expansions. According to arguments from the ESA, loosening DMCA restrictions with regard to games would hurt publishers’ bottom line should they ever decide to reissue a classic game.

And there is certainly some merit to that argument. This week, Limited Run Games announced it would release over 20 classic titles, including beloved favorites like Jurassic Park for the NES, Tomba!, and Gex. Limited Run is also releasing a previously canceled Game Boy Advance game called Shantae Advance: Risky Revolution, which will be available to play on a Game Boy cartridge.

For its part, the ESA has pushed back against the idea that it’s hindering preservation efforts.

“It simply is not accurate that the industry has opposed efforts by libraries to have legal access to games for preservation purposes,” Stanley Pierre-Louis, president and CEO of the Entertainment Software Association, said in a statement to The Verge. “We believe that preservation can — and should — be accomplished without jeopardizing video game companies’ rights under copyright law.”

Interestingly, the Video Game History Foundation did not share what it thinks should be done. That wasn’t the goal of the report.

“What we’re asking with this report is for the game industry to acknowledge that most classic games are out of print,” Salvador wrote. “And that the commercial market alone can’t solve this.”