Changelog for Patch GOG-4 (Windows) (28 June 2016):

- Language selector fixed


Changelog for Patch 24360 / GOG-3 (Windows and Mac) (added 05 October 2015):

Bugs fixed :
- Fort Mason: Game crashes to desktop when guards are locked in
- Fort Mason Challenge 1: Not all optional treasures can be collected
- MacOS: Focus loss caused permanent mouse invisibility
- Savegames: Exit in Museum sometimes not useable after loading story_autosave

Other :
- Added J and K as hotkeys for camera Zoom
- Added tutorial instructions for magic mouse (mac only)
- Updated GOG API and added expanded leaderboard functionality

I still don't see a new patch, or is it in the game download?

Not there?

I don't have this game, but often the patch comes in the form of an updated installer instead of a separate file.
Do you remember if the previous installer was GOG-3? See above, unless you mean that the language selector is not fixed in the available GOG-4 installer, in which case you should ping a blue-text.

Changelog for OSX hotfix / GOG-4 (Mac) (added 12 January 2017):

- Corrects language selection issue - language will now correctly switch based on system language

I would like to play the game in English even if my OS is in French. Isn't there a language selector for MacOS?

Based on the wording of the changelog, the in-game language depends on the OS one.

Sorry I can't offer you any real help, I don't own the game. My suggestion is to contact GOG Support and inquire about it, and if there's no language selector, perhaps even contact the dev/pub and inquire/request it.

Changelog for update (added 04 December 2017):
[Windows Only]

- Installer maintenance update - No game files were changed.

what does "installer maintenance" mean? It seemed to install just fine last month. Was there a reported bug?

You know, the important stuff, enhancing the installer's fonts, adding some advertising pics and fiddling with the Galaxy compontents ;-P

But seriously, I don't know. We've had tons of these updates for a lot of games lately, mostly for Windows installers, but also some for Mac. There have always been installer maintenance updates, but we usually didn't get a changelog notice for them.

Changelog for installer update / (Mac) (added 16 December 2017):

- Installer update - No game files were changed.