In my gamelist there are some games marked as "game has updates waiting for you".
Is there any possibility to see what was the old version and what is the actual version?
I dont use galaxy, use direct download files.

The most reliable way is following this thread:
https://www.gog.com/forum/general/the_what_did_just_update_thread

Sometimes GOG provide changelog for updated installers, but they often miss it.
And GOG often make stupid typos so you will see the wrong version on website.

For example, pathfinder_kingmaker_1_0_9c_24479.sh was showed as 1.0.8b yesterday.
While they fixed the stupid bug today, some old typos never got fixed.

Thanks!