The weirdness ramps up over time, but at a rate that doesn't get overwhelming. Each part is basically a standalone story, and in most cases an entirely separate genre from previous parts. Part one is a straight up vampire hunter story sort of like castlevania. Part two involves nazis and the occult in World War II era New York. Part 3 is basically around the world in 80 days. Part 4 is a small town murder mystery. The change keeps each part fresh, but a lot of the weirdness you see builds up from part to part.