My friend, who is Polish, failed three times. And another friend's wife failed eight times before she passed.
That's because the tests are recorded through four separate cameras, as well as through in-car microphones. The test isn't difficult, but you need to drive in accordance with the rules and be very clear if there are problematic situations. For instance, if someone is standing next to a zebra crossing but not actually crossing. You should stop and wait for them to cross, but if they don't cross, you should clearly ask the examiner for permission to continue.
I passed first time here and without any mistakes, but I spent a *lot* of time revising potential routes. I would go out in the evening and ride buses around the part of Poznań where the test centre is, and then I'd also walk around the district to make sure that I knew about any potential problems. It paid off handsomely - I had this tricky left turn to make that really required previous knowledge of the area.