I just picked this up because it was listed for both Windows and Mac, but when I went to install it, there was only a Windows version. Anyone know what's up here?

At the bottom of the store page, it's noted that the OSX build is running late. We should have it by the end of the week.

Edit: Just got back the official fix, fetch the game with the GOG Downloader instead of a browser. Safari, and probably others, add a quarantine xattr that carries onto the executable.

And the Mac build is broken, on 10.8 at least. I suspect the problem is that they signed the app, but not all of the frameworks inside. It's a known broken thing in Apple's development tools, with maddening workaround spells.

Ah, the workaround is to either turn off Gatekeeper entirely, or run from the terminal. Right-click and Open does not cut it, the app is just dismissed as broken and you are offered a 1-click solution to trash it. The most straightforward-ish way to run in the terminal is with Finder, Show Package Contents and find Contents/MacOS/CaveShooter. Drag that file onto a Terminal window, and press enter.

You might want to let GOG know.

I did not know GOG had that. Thanks for the link, the problem is now reported.

Edit: saying it here too, in case if anybody's looking - the fix is to download via the GOG Downloader. Not your browser.