How to Install Epstein Island Game on Windows, macOS, and Linux, Warnings Included

Which file goes with which system

The download page has exactly one file per system, and the name tells you almost everything: island, then the version, then the system. Windows and macOS get a ZIP, Linux gets a tar.gz. There's no setup wizard; the program runs straight from the unpacked folder.

The Windows and Linux builds target 64-bit machines with x64 processors. The macOS package is a universal app with code for both Apple Silicon and Intel Macs, so there's no second version to pick from.

Make some room on your drive. As of version 0.15.2-wasser, the Linux archive is 209.2 MB, the Windows ZIP 243.2 MB, and the macOS ZIP 310.9 MB. Unpacked, each one takes up roughly twice that, and the updates the app fetches later go into its own user data folder on top.

What SmartScreen and Gatekeeper are actually telling you

Both warnings have the same root: the packages don't carry a signature from a known publisher. Island.exe has no code signature at all. The macOS app is only ad hoc signed, meaning there's no Apple developer certificate behind it, and it isn't notarized by Apple.

Windows responds with the SmartScreen filter, which it shows for new programs. macOS says “Apple could not verify …” and offers “Move to Trash” right away. What both are saying: the system can't confirm who built this file. Neither message says anything was found inside it.

So checking that the file wasn't altered on the way is up to you, and it takes under a minute. Linux has no comparable gate for Island.

Staying safe: check the checksum first, then allow the app

Before you click past any warning, compare the SHA256 checksum. On your system's card, open “After the download”; the value is right there, with a “Copy SHA256” button. The checksum belongs to the archive, meaning the ZIP or tar.gz file, not to the unpacked program. So check it before you unpack.

If the two strings match, your file is exactly the one sitting on the server. If they don't, don't run anything from it: download it again and let the team know, which is also what the download page advises.

After that, allow this one program and nothing else. “Run anyway” and “Open Anyway” apply to Island only, and protection for every other program stays on.

• Windows, in Command Prompt or PowerShell: certutil -hashfile FILE SHA256
• macOS and Linux, in Terminal: shasum -a 256 FILE
• Replace FILE with the full file name, for example island-0.15.2-wasser-windows.zip in your Downloads folder.

TipOnly download the packages from the download page, because a copy passed around in a chat or forum has nothing to compare against.

Step by step: setting up on Windows, macOS, and Linux

With a verified archive, it only takes a few moves on each system:

• Windows: right-click the ZIP and choose “Extract All”. Inside the Island folder the ZIP contains, Island.exe sits among more than a thousand files the program needs, so keep the folder together. On first launch SmartScreen shows its notice, and clicking “More info” reveals the “Run anyway” button.
• macOS: double-click the ZIP, launch Island.app, and choose “Done” in the message. The old right-click and Open trick is gone as of macOS 15. Instead, head to System Settings, Privacy & Security, scroll all the way down to “Open Anyway”, and confirm with your password. From then on the app opens like any other.
• macOS via Terminal: xattr -dr com.apple.quarantine ~/Downloads/Island.app removes the quarantine flag from this app only. If you've already moved it to Applications, adjust the path.
• Linux: unpack with tar -xzf and the file name, then run ./Island/Island. The program inside the archive is already executable, so you don't need chmod.

Linux: what the SUID sandbox message means

On Linux you may get a message about the “SUID sandbox” at launch. The cause is in the package: the bundled helper file chrome-sandbox doesn't have the setuid bit set. For that case, the download page tells you to start with ./Island/Island --no-sandbox.

The switch does exactly what its name says: the program then runs without that sandbox. So only use it if the message actually shows up, and only with an archive whose checksum matched.

Desktop app updates: what refreshes itself and what doesn't

The app asks the server for new content at launch and then every 30 minutes. When it finds some, it downloads it quietly in the background, and only the files that changed. Each one is checked against the size and SHA256 value in the server's file list, with up to three attempts if something goes wrong.

Once everything is in, a bar in the bottom left says the update is ready and takes effect on the next launch. “Jetzt übernehmen” (apply now) switches over immediately. If the connection drops, whatever was downloaded stays put and the next attempt picks up from there. Offline, you simply play the version you have.

There's one limit: the program itself, the shell around the game, doesn't update itself. When a newer shell exists, the bar tells you there's a new program version to download. Grab the current package from the download page, check its checksum, and set it up just like the first time.

The app's menus are in German for now. Under “Spiel” (Game) you'll find “Nach Updates suchen” (check for updates, Ctrl+U, or Cmd+U on a Mac), “Update jetzt installieren” (install update now), and “Geladenes Update übernehmen” (apply downloaded update). On Windows and Linux the menu bar is hidden; press Alt to bring it up.

TipOn a slow connection, launch the program with --kein-auto-update, and it will only check without downloading anything on its own.

If the app won't start or acts up after an update

Island opens a single window. Launch the program a second time and it just brings the existing window to the front. The reason: the app runs the game through a small server on your own machine, at 127.0.0.1 on port 47311, and your dev profile is tied to that port. If the port is taken, it moves to 47321, 47331, or 47341. If all four are busy, no window opens.

If something breaks after an update, the entry “Auf mitgelieferten Stand zurücksetzen” (reset to the bundled version) in the “Spiel” menu helps. It switches back to the content that came with the downloaded package, which every update leaves in place. The app also spots an incompletely downloaded version by itself and falls back to the package automatically.

If none of that helps, write to the team with your operating system, the version, and what you did last. Contact details are in the FAQ. For where the game stands overall, see Development Status.