Ooo! Sooo I have designed three houses!
One is in my gothic forest town, Odanah.
Mayor?s house:
Entrance ~ cemetery 
Back room ~ room with black roses, Pipe organ and brown rococo furniture
Left room ~ gothic library room with bookcases, spinning wheel 
Right room ~ purple rococo furniture with creepy wall and floor
Upstairs ~ gothic princess room with white rococo furniture, dollhouse, creepy skeletons
Basement ~ horror room with a maze walkthrough
In my second, brighter and celestial-based town Lumina, I have two houses I?m creating!
Mayor?s house:
Entrance ~ galaxy floor and lunar horizon, sun, moons and asteroids, alpine furniture with night sky tee fabric
Back room ~ a library and historical research room with large bookshelves and old globe, vintage telescope/ telephone
Right room ~ a Native American themed space room with customized cabin furniture
Left room ~ a lunar surface room with lots of asteroids
Upstairs ~ I?m still not sure about this - I was thinking a space launch room, or a mars- themed space room with the lunar rover. I?d have to do custom qr?s But I don?t think it would be that difficult!
Basement ~ a spaceship room with laboratory capsule, monitor tower, sci fi flooring and wallpaper
Second characters house:
Entrance ~ not entirely sure what to put in the entrance, maybe a mix of all gamer items!
Back room ~ Mario Kart room with closed road, karts, triple shells and triple bananas
Left room ~ Zelda- themed room with all Zelda furniture and flooring/ wallpaper
Right room ~ Mario themed room with all Mario items, lots of blocks and ? Blocks
Upstairs ~ arcade room with arcade machine, pinball machines, and all gaming systems (3DS, Wii U console)
Basement ~ boo?s mansion themed room in a library with coins