The Rare Replay collection came out this past week, to nearly universal acclaim. It’s an incredible collection of mostly incredible games from over two and a half decades of gaming history, and it serves as a reminder of just how far the medium has come in that time. But it also serves as a reminder of just how difficult it is to preserve our history.

Rare Replay is a collection of 30 games for 30 dollars. It collects titles from throughout the developer’s lifespan, from the ZX Spectrum, from Nintendo platforms, and from the Xbox and Xbox 360. It’s wrapped up in a positively charming theater-like package, and filled to the brim with bonuses, features, and development documentaries. It is, in short, everything you could ask for from a package like this. Except, well… there are a few more things you could ask for. And those things highlight why Rare Replay is one of an extremely rare kind.

The first, and most obvious thing we could ask for is GoldenEye. Donkey Kong Country. Star Fox Adventures. (Okay, I recognize that I’m probably the only who wants Star Fox Adventures, but I mean, come on! It’s like Zelda but with freakin’ space dinosaurs!! —okay, okay, not the point.) The point is that these games are all tied up in licensing issues that have prevented and will continue to prevent these games from appearing in this kind of collection. GoldenEye is a movie license. Donkey Kong and Star Fox are Nintendo properties.

And Rare’s not an isolated case. These kinds of problems exist throughout the industry. Every classic game that LucasArts ever produced is locked up somewhere in Disneyland. It took years of effort on the parts of many individuals to bring games like Grim Fandango out of licensing hell. But in many–perhaps most–cases, rights holders don’t even know or care what they have.

Kotaku ran a story earlier this year about the classic PC shooter, No One Lives Forever, and how its rights are tied up somewhere between Warner Bros, Activision, and 20th Century Fox. In every case, the potential license-holders either didn’t what, if any, piece of the game they owned, or didn’t care enough to work to keep the game available.

If you look at the world of film, basically every movie of the past hundred years–from Citizen Kane to Jackass–is currently available in some format or another. And this kind of preservation is essential to the development of a medium. While we’re making strides with services like Gog and Nintendo’s virtual console, there are still hundreds, maybe thousands of games that we’re losing to time.

The other problem is the technology powering these games. Rare Replay is an odd patchwork of different emulation solutions. The older games are emulated to an excellent standard, but more recent ones, like those running with the much-ballyhooed 360 backwards compatibility, do have framerate problems and other minor issues. These issues highlight the difficulty of making games work on different platforms.

The technology of other mediums is mostly static. The way movies are made has changed dramatically over the years, but the end result is still just a moving image displayed on a screen, a product which can be endlessly, effortlessly transferred to new types of recordings.

But games interact with their hardware in complicated and often unpredictable ways. The game itself and the hardware that displays it are inseparable. Early PS3s were backwards compatible because they had a PS2 processor literally built inside–one of many reasons why that system was 599 US dollars.

Most other forms of backwards compatibility are provided through emulation, which is a solution fraught with its own difficulties. Even once you’ve figured out how to make a working emulator, it’s still tied to the hardware you’ve designed it for–meaning that Microsoft’s going to have to develop that 360 emulator all over again for the Xbox Two. (You know, the fourth Xbox console. Xbox Two.) Solving the problem once doesn’t solve it forever.

I don’t know if we’ll ever figure out a way to keep games alive in perpetuity. It’s a tough, expensive process that doesn’t really help a big company’s bottom line. The closest thing we have to solutions are the endless open-source emulators and ROMs which populate the internet, but that brings us to the ethically grey and legally very black world of piracy. And in 50 years, when most everyone who remembers the NES is gone, who’s going to care enough to keep that emulator updated and running?

It’s a tough question, and one that paints a pretty bleak picture for the preservation of games going forward. For now, all we can do is enjoy the occasional gem, like the passionately curated, beautifully designed museum of Rare Replay.