Just like in the title. I want to buy the game, because I played it many years ago. The description on the main page of the game says that there is only English and German available.

Don't think so. Neither does it have the Czech version.

I have the disc with the Czech version and can get the Czech voice acting simply by overwriting the english voice lines with those from the disc. So if you got your hands on the Polish version, you could probably get the Polish voices to work.

But I found no way to swap text language. There is some formatting error and the text becomes illegible if I replace the text files too. The english version probably lacks the encoding for special letters like those from Polish or Czech, so the game can't deal with it.