Generally, it's referred to as "All Saints Day".....which leads back strangely enough....to Martin Luther and his fight-to-the-death with the Catholic Church. This is the day in 1517 that a written war of sorts started and ended the Catholic Church domination of German society. So, there is a remembrance of sorts.....over the spirits of the dead.
The occasion eventually brought in some ceremony of sorts, and sweets. For several hundred years....it was a simple affair. The American commerization kinda changed things.....but Germany has lagged behind the American extreme of the night.
Trick or treat enthusiasts? In the average German town......you might have a couple of kids who put on some make-up and a suit, and do it. But it's not really a big trend.
Costume parties? Well, it's started....but it's not a big trend.
Halloween movies or such? Well.....it's started, but it's not a big trend. Last night, they featured the Walking Dead zombie series....but only after 11PM.
Maybe in twenty years....Germans might eventually catch up. Times change....people change....cultures change. The amusing part of this story? All leads back to Martin Luther....who probably would be shaking his head today over some silly created tradition.