Okay, thanks for the hint.

https://www.dropbox.com/s/dffzyk3mqw6wjn3/Sponk3.zip

I am experiencing a similar, if not the same problem.

I've played for several hours, no problems whatsoever, then, the game started freezing midgame. I tried reloading several times, a complete reinstall of the game. No use.
Every time I load the save game file I will put in as an attachment, the ...