Fitting a Game Onto a CD

Mon, 15 Jun 2026 07:27:49 -0400

A friend of mine had kindly gifted to me a copy of Mina the Hollower. For those not in the know, this is a top-down, tough-as-nails, 8-bit style adventure game that plays similarly to the classic Zelda titles on the Game Boy, and was recently released by the same guys who made Shovel Knight. In addition to a Steam key, the Humble Bundle gift also included a DRM-free copy.

Can We Fit it Onto a CD?

Upon extracting the contents of the DRM-free tarball, the game contents hover around 846 MB. The Curious George in me, upon discovering this file size, wanted to know if I could compress the contents to under 700 MB – the file size limit for a CD-ROM. Kazeta – the operating system that boots games from physical media – has the ability to load compressed games as Enhanced Read-Only File System (EROFS) or SquashFS images, with the .kzp file extension (or, at least the latest development build of Kazeta supports this, at the time of writing this). So, using the strongest compression algorithm, LZMA, I compressed the game. The resulting file size ended up being 749 MB.

Dang…so close! So I investigated further by digging into the file contents of the game itself.

Going inside of the game folder, right away there’s a file I can delete: libsteam_api.so. I’m not even sure why this file would be included in the DRM-free build; we don’t need Steam running in the background while playing this game, after all. So deleting that file saves a whopping 379 KB. Yeah, we’re gonna have to do a bit more here if we’re going to get under that 700 MB file size.

This is where I started asking Google Gemini what I could do. I sent it the file/folder structure of the game along with the associated size of each file. It suggested that I could delete a few game controller mappings – namely, gameControllersOsx.cmap.yc and gameControllersWin.cmap.yc, since I’m only testing the Linux build and these files are irrelevant. However, these files are very small at 93 KB and 250 KB respectively, so it wouldn’t help me much with trimming the file size down.

We can save some space on the binary file itself. Uncompressed, the binary file sits at around 27 MB. Running strip --strip-unneeded MinaTheHollower in a terminal, this ended up saving about 7 MB of unnecessary debugging symbols. Next, we can make use of the Ultimate Packer for eXecutables to compress the binary even further. The resulting file size for the binary is now 6.8 MB.

Compressing as a LZMA EROFS image again, the resulting .kzp file size is 745 MB – only 4 MB smaller than with the uncompressed binary.

The LLM ended up doing something interesting after some trial and error. Upon seeing this big, fat 600 MB default.sndbnk.yc sitting inside of the “data” folder, it ended up creating a Python script for me. The script would do the following:

Read said sound bank file in binary mode and scan for Ogg Vorbis magic numbers.
Extract said audio streams and downsample them.
Inject the smaller audio streams back into the container at their original offsets.
Pad the remaining space of each extracted block with zeros so the file’s original internal offset tables don’t break.

I ran the script, and the file size remained the same. However, after compressing the game now, the .kzp image ended up being 548 MB! Plenty of space now to fit onto a CD!

Now, in order to test this on Kazeta, I had to supply the .kzi metadata file, along with a 32x32 PNG icon for the game. So the contents of the cartridge looks like this:

$ tree -h -L 2
[   62]  .
├── [  136]  mina.kzi
├── [ 2.6K]  mina.png
└── [   38]  minathehollower
    ├── [ 4.7K]  data
    └── [ 6.8M]  MinaTheHollower

3 directories, 3 files

The .kzi file is as follows:

Name=Mina the Hollower (Compressed)
Id=mina-compressed
Exec=cd minathehollower && ./MinaTheHollower
Icon=mina.png

Note that no runtime is needed for this.

To compress this as an EROFS .kzp image, you put the contents of your game inside of a folder. Then you’d run something like this in the parent directory: mkfs.erofs -z<compression-algorithm> <name-of-image>.kzp <name-of-folder-to-compress>

In this specific instance with Mina the Hollower: mkfs.erofs -zlzma mina-the-hollower.kzp minathehollower/

Note that, per the EROFS documentation, you can use several types of compression. LZMA has the strongest compression, so that will give me the smallest file size. The smaller the file size, the better, because when we burn this game onto a CD, the less time it will take for Kazeta to read the game data.

After testing the Mina .kzp package on an SD card with Kazeta+ and verifying that the game runs, my next task was burning the image onto a CD. I made an ISO with genisoimage, and burned it with Brasero. Put the disc into an $80, ten-year-old Intel NUC…and low and behold, it runs! As I’ll get into later on, though, there were some strings attached.

Making Artwork

Getting Mina the Hollower small enough to fit on a CD and burning said game onto it is one thing. But labeling the ordinary, gray-colored front side of the disc with “MINA” with a Sharpie and slapping a glossy adhesive on it with the game’s artwork turns the disc from a basement project into something that you might find at a brick-and-motor store. Something that looks a lot more professional, and gives beautiful eye candy.

Steam Game Covers is a website that offers free CD/DVD templates for most, if not all, of your favorite Steam games. Fortunately, there is some custom artwork for Mina the Hollower – an optical disc label, and a DVD case cover. Now, obviously, since we’re not using Steam while playing this game on Kazeta, what I did was replace the Steam logo with Kazeta’s, using GIMP. I also converted the dark blue background to black. Using adhesive, glossy photo paper in my inkjet printer, I then printed both the CD label and the DVD case cover, cut them out with a pair of scissors, then put them in a spare, unused Wii game case that I had lying around. My only problem was both labels were slightly smaller than I had wanted them to be, hence why you see in the photos the labels don’t quite fit they way they were intended.

If I wanted to go the extra mile, Mina the Hollower has an in-game instruction manual. I could probably find a way to make a PDF out of it, print it, and stick it on the left side inside the case. But that’s a project for another day.

The Drawbacks of Optical Media (And DRM-Free Gaming)

Using physical media has sort of made me realize how much we take for granted when it comes to modern-day gaming. Though optical media may be a less expensive alternative to flash-based media, such as SD cards, the most glaring issue when it comes to playing Mina through a CD is the loading times. Loading the game from a SD card only takes a few seconds. Now multiply that about 20 times, and that’s how long it takes to boot the game. But it’s not over after that. After creating a new save file, I waited another minute or two before the game loaded. Fortunately for us, Mina comes as a native Linux binary, and we don’t need to make use of the Kazeta Linux runtime. If I were to use the Windows version of the game, load times would be drastically longer, since we would also have to make use of the Kazeta Windows runtime (if you’re curious, you can see some of my experiments with loading times on the Kazeta+ Wiki).

Now I understand that, even if a modern console has a disc drive, it’ll install some of the game data onto the internal hard drive prior to running, to compensate for what would probably be excruciatingly long loading times.

Another side effect that comes with CD-Rs is, once the disc is burned, you obviously can’t write data to it again after that. I’ve noticed there’s been a few updates to Mina the Hollower since the time I burned the game onto the CD. I’m stuck with the version that I have on the disc. So I would either need to resort to re-writable disc media and re-write the disc with the new update, or find a way to store game updates on Kazeta’s internal hard drive.

Also – this applies to DRM-free games on any physical media, not just optical discs – is the lack of convenience when it comes to cloud-saving support, as well as not being able to easily apply updates to a game with just a click of a button. If, for example, I were to go back and forth between playing Mina on my Steam Deck and my Kazeta console, I would have to manually dig into the game files, find the save file, then copy it over to the appropriate place on the other device. Kazeta does not make this necessarily easy out-of-the-box; I’d have to copy the save file to a SD card, put it into the Kazeta console, log into the terminal, and run a copy command to Kazeta’s save directory. Then I’d have to do vice-versa if I were to transfer the save from Kazeta to the Steam Deck. SSH definitely comes in handy for something like this.

When I was gifted Mina, it came from Humble Bundle. The DRM-free build, as far as I’m aware, has no download options for downloading the latest update. Downloading the build now, it’s at version 1.0.4. The Steam version currently sits at version 1.0.6. So I guess it would be up to the developers to update their build on Humble if I wanted to use the latest version.

I Own the Game

All of this being said, Kazeta is special in its own way in that, it enables us to create our own physical media for the games that we love. I truly own my copy of Mina the Hollower. Should one day Steam or Humble Bundle no longer be a store front, this CD will always remain. I will always have access to this game. And all I have to do to play it is pop in the CD in a disc reader, connect it to my Kazeta “console”, and select the “PLAY” button. No need to hop through five different menus. No need to worry about updates. No need to connect a keyboard and mouse to log in.

As a small side bonus, Yacht Club Games hasn’t yet released the official, physical version of the game. I essentially took matters into my own hands and made my own copy ahead of time. No need to worry about when “later down the road” will be.

Gosh, I love how Kazeta makes a nostalgic throwback to the way we gamed in the 1990s. Even if I had to put in all that extra labor to make sure Mina the Hollower works, and finding a way to compress it down small enough to fit onto a CD.

Mina the Hollower on Linux Gaming Central

Fitting a Game Onto a CD

Can We Fit it Onto a CD?

Making Artwork

The Drawbacks of Optical Media (And DRM-Free Gaming)

I Own the Game