I've bumped into a couple of phrases that had me scratching my head longer than I probably should have (without spoilers, level 4 comes to mind), but I'm not sure I wholeheartedly attribute that to any sort of Finnish-to-English translation issues so much as I just consider it a byproduct of the land and language the game is set in. Text puzzles like that are always going to be a little tricky depending on your demographic or vocabulary, I suppose, but overall I think where absolutely necessary the language has been clear enough to make sense.
Of course if you're struggling on a particular piece of dialogue or written text, you can always seek help in the Hints forum. I'm sure there are numerous users (myself included) who would be more than willing to help clarify what you are reading.
