Not a big thing in Poland but it's present. Kids have fun going around their neigbourhood after dark (smaller ones usually under their parents' watch) hunting for candies, young-to-middle-age people get an excuse to throw a party. It's mostly a curiosity, not something people wait the whole year for or go out of their way to decorate their house like in the US. I personally don't enjoy dress-ups but if kids are having fun and the religious people are getting triggered because of a "western, non traditional, pagan custom", then I'm all for it.