For most every kid in my family, ages 2-4 is where we had to start keeping “monster spray” by their beds, or they freaked out about monsters in the closet, or started saying stuff straight out of a horror movie (My son used to say their was a ghost who lived in our grandfather clock who only came out when I left the room.) I still have vivid memories of a nightmare I had at that age where a Purple Pie Man toy came to life and after that I refused to have villain toys in my room.
I think a Villain’s Land would be a lot of fun and not scary for those aged 7+. But the fear of “bad guys” with toddlers and preschoolers is a real thing.