Changelog for update 1.4 / GOG-18 (Windows) (added 21 January 2016):

- The Dolphin is now available in your seas!
- Natural Gas can now be mined!
- The Chinese crane can now roam your swamps!
- The Azure lakes are now available in your forests!
- The Oak Tree can now grow in your forests!

Wow, new content? I should clearly check subforums more often as I had no idea about this and it's been six months. xD Thanks, PaterAlf!

Changelog for Patch 1.5.1 (added 23 May 2017):

- Mac and Linux versions for Reus! We’ve eliminated crashes and improved performance. -
- Reus should now run great on Mac and Linux.
- Overall better performance and small quality of life improvements, like much requested improvements to the UI text.
- Official Chinese Translations!

Playing on 1.5.1.
Everything was great until a town starts. Too slow on Mac 10.13.2. Not even 1 fps.

Changelog for Patch 1.6.5 / GOG-20843 (Windows) / GOG-20918 (Mac) / GOG-20844 (Linux) (added 18 May 2018):

Additions & Balance
- Unlock all mode where you can play with all nature sources unlocked in Freeplay mode. This means you do not need Developments/Achievements to be able to transmute natural sources in higher level sources (f.e. Whales, Sunflowers, Silver, etc.). Unlock All mode is not available in Era mode. You still need to unlock natural sources the old way there.
- Fluorite now gives +40 Tech, +5 Awe per statistic over 10 (from just +25 Tech per stat).
- Main Menu news window

Natural Sources fixes
- Fixed Superior Beaver: Gives 4 Wealth instead of 2 (Great Beaver gave 2 already).
- Fixed Cacoa Tree: Gave +25 Awe instead of the advertized +25 Flora if a mineral is next to it. Now actually gives +25 Flora.
- Fixed Sunflower: Fertile Biome now also works for Great Oak.
- Fixed Greater Komodo Dragon: now has range 2 instead of 1, just like the vanilla Komodo Dragon.
- Fixed that Quartz, Agate and Stone no longer evolves into Salt with both Crystal and Seismic aspects, just with the ones that are advertized.
- Text: Great and Superior Ginger displayed wrong Flora bonus (+5/+5/+5 instead of +5/+9/+16)
- Text: Superior Rattlesnake displayed +3 wealth instead of +4 that it gives.

Projects fixes
- Fixed Clothing Factory for the Factory: Works with Yaks as it is supposed to.
- Fixed Three Pheasants for the Tavern: now also works on Boars.
- Fixed Mining Invention for Inventor's Tower now also works on Copper, since it has an evolution path through Seismic from Marble.
- Fixed Licensed Breakthrough for the Observatory now also works on Superior versions of the required plants.
- Fixed Project bonuses that give bonuses for all value of a certain stat within a civilization range. Specifically they now also give bonuses for the city center patches and the patch on which the project stands itself.
- Affected project bonuses:
- School: Outdoor Classes
- Mad Scientist: Cloned Army, Brilliant Discovery
- Mad Scientist: Brilliant Discovery
- Market: Prized Preys
- Workshop: Sweatshop
- University: Botanical Course
- Sacrificial Altar: For the Gods
- Nature Park: National Treasure
- Circus: Spectacular Arena
- Monument: Inspiration
- Tutorial Shrine: Greed Express ^^
- Text: Blast Furnace's Agricultural Machinery bonus now properly advertizes that it only gains +1 Tech, +1 Wealth for each 2 food gained through it's bonus.
- Text: Lighthouse's Clear Blue bonus now properly advertizes that it stacks up to 6/4 times (depending on common/rare version).
- Text: Barracks' War Preparations now has wording that reflects it bonus.

Misc fixes
- Fixed: Removed short hang when creating an ocean or mountain for the first time.
- Text: RXotic Aspect -> Exotic Aspect
- Text: Added missing completion texts for projects in English descriptions.

Great that after all this time the developers are still working on improving this awesome game!
My thanks to them and to you guys that keep track on changelogs.