The Spiral, a 1978 Polish film has nothing particularly wrong with it; the acting is decent, the writing didn't make me wince, which places it above 70% of old films and 90% of new ones. I tend to avoid 60's and 70's films because they are often dominated by sex or gore, this one wasn't. It's a slow-burner about one man's descent into hopelessness and suicide. It will no doubt frustrate Hollywood action fan types (unless they've run out of Ambien).
It's hard to pinpoint what's wrong with it, it's like a Bergman film without the genius. A Fassbinder film without the daring dialogue. I felt the makers were holding something back, something important.
At the beginning, I kind of wanted to step in an talk to the main character (and occasionally to smack him) which says something about how provocative it was. But my interest in him lapsed as the film progressed, and just as well. since no answers or explanations ever eventuated.
In the right mood, it could be relaxing, in the wrong, dead boring.