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Here is the video if anyone wondering.

I tried with and without internet. In both versions(GoG and Steam) you can't open your chests without internet connection. Those chests drops experience points or a hat(collectible fashion items).

I understand why they did this way. You can sell those items(hats) on Steam's marketplace but why did they implement it to GoG? As far as I know there is no marketplace to sell items on GoG.
Actually it's a bad practice because there is not much of these "hat items" it's not a big game it's just 6 hours long. But why did they implemented such a thing to this game I don't get it.