Who doesn't want to be a princess? This castle comes with two basic materials that give it a shiny pink and blue finish, making it look like a bouncy castle or something out of a Barbie movie. But, different materials can easily be applied to make it look more realistic.
Feel free to use this mesh however you want. You can use it as is, or expand use it as the basis for a more complex castle. You can even remove subsurf to get less rounded off edges.
Note that even though it looks like a doll house, this mesh is quite large. If you import it into a game engine such as unreal, expect something castle sized, not something toy sized. The castle is roughly 300 meters wide, 200 meters tall, and 100 meters in depth, give or take a couple dozen meters.