Re: I would like to publish by jumpbox my translated version of Barotrauma to Polish. Do I need permission?

Yes, feel free to publish it. :) There's one thing to note though, the EULA prohibits releasing standalone versions of the game, meaning that you should only release the files needed to translate the game, not a full game that works out of the box. At this point it doesn't make much difference because the game is available for free anyway, but something to keep in mind.