It's not necessary to have a particular theme in order to enjoy New Leaf. Themes can help with town planning and landscaping if that's what you want to focus on, but the essence of the game is to make it what you make it. There is also a category of non-themed towns if that's of any help. For years I've played just to play: collecting items, getting to know villagers, filling my encyclopedia and museum, and just generally using the game as a place to escape for a bit. It was only in the last few months that I started a "themed" town to try out new things. Themed towns are just another way of using the game, but are not required in any way for gameplay.
