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Are there any differences between the GOG version and the Steam version. I already own the game on Steam and was wondering about this.

Thanks in advance for the feedback.
You don't need to use Steam?

I'm not sure what you're expecting. It's the same game, just drm free.
And it is a HUGE "just"
MASSIVE "just". Not having to log in to some server to check you're not being a naughty boy all the time is the main reason I buy games here (having to do this just once for any game is once too often IMO - DRM IS THE ENEMY OF THE PEOPLE!). That and the prices... ;)