It seems that you're using an outdated browser. Some things may not work as they should (or don't work at all).
We suggest you upgrade newer and better browser like: Chrome, Firefox, Internet Explorer or Opera

×
Anyone know? I couldn't find a changelog on Steam to compare
It should be as complete as can be; I don't recall there ever being any significant updates to this game.
What i can say is, the Linuxversion is older, than the Windowsversion. Sad, but true. But another time, GOG don't care about it (anymore?). This is now the 4th or 5th game, that hasn't been updated for a looooooong time.
According to SteamDB, the Windows and Mac builds on Steam have not been updated since release, so the GOG builds should be up-to-date. The Linux build on Steam was updated once on 4/21/2016. According to GOGDB, the Linux build on GOG is versioned "20160421" so it looks like the Linux build is also up-to-date.